Wednesday, 20 March 2013

The Secret of Greek Fire - The Umayyad Sieges of Constantinople

In the second half of the Seventh Century the Byzantine Empire faced an increasing challenge at sea from the Arab invaders who had swept into the Middle East, destroyed the tottering Persian Empire and driven the Romans out of Egypt, Palestine and Syria.

With the possession of these new lands came also the advantage of access to the Mediterranean along with the vital infrastructure of ports, ships and sailors with which to exploit it. Arabs were not natural seafarers and indeed the Caliph Umar had advised against embarking on any nautical adventures but the new governor of Syria Muawiya understood that Byzantine command of the sea made his territory vulnerable and he was determined to challenge the Empire’s naval superiority. He had begun in 649 with a raid on Cyprus, just a short hop across the water from the Syrian coast. Muawiya led the raid in person and inflicted considerable destruction on the port of Constantia which was of great strategic importance to the Byzantine navy. Three years later he dispatched a highly ambitious expedition comprising two hundred ships to attack the coast of Sicily in a hit and run campaign. A second attack on Cyprus was followed up by an attack on Rhodes. Amongst the plunder taken away were the remains of the fallen Colossus, whose great bronze carcass was sold to a Jewish scrap metal dealer.
The Battle of the Masts 655 (from an 1889 engraving)

In 655 the emperor Constans II had received intelligence that Muawiya was planning something bigger; an attack on Constantinople itself. Determined to drive the Muslims from the sea, the emperor took command of the Byzantine fleet in person and set out confidently to bring Muawiya’s fleet to battle. Constans had reason to be confident. His ships outnumbered those of the enemy by at least two to one and the Byzantine crews were far more experienced at fighting at sea than their Muslim enemies. The two fleets encountered each other in coastal waters off Finike, roughly half way between Rhodes and Cyprus. The light was fading and so both fleets anchored for the night, agreeing a truce until the morning. The next day dawned with sea conditions calm which must have been a great relief to the commander of the Arab fleet. The lack of wind had deprived the Byzantines of the opportunity for swift manoeuvre which may have allowed them to overcome their inexperienced opponents and instead the engagement known to posterity as the Battle of the Masts would be fought hand to hand at close quarters. The Arab ships closed with the Byzantine fleet and hurled grappling lines to ensnare the enemy vessels and allow them to be boarded. Fighting with their usual ferocity, the Arab attackers overwhelmed the Byzantine crews and the battle began to swing in their favour as they hacked their way from ship to ship until the imperial flagship itself came under threat. Fearing for his life Constans persuaded one of his men to exchange clothes with him. Having switched his distinctive imperial regalia for the nondescript outfit of an ordinary sailor, Constans escaped to another ship which carried him to safety whilst the defenders of the flagship fought furiously and were cut down protecting the imposter.

It had been a shameful defeat for the Byzantine navy, the remains of which limped back to Constantinople, there to await the inevitable attack on their capital by the victorious Arabs. The expected attack did not come however for the Muslims, who had until now remained united, were about to be plunged into the uncharted waters of civil war, thereby granting a welcome respite to their enemies.

Following the death of Ali the Fourth Caliph and son-in-law of the Prophet in 661, Muawiya found himself as ruler of the Muslim world. With his empire secure he focussed his attention once more on the final defeat of Byzantium. In 672 his fleet seized and fortified the peninsula of Cyzicus on the eastern shore of the Sea of Marmara, from where Constantinople itself could be directly threatened. His son and heir Yazid was sent to command the attack on the city. Victory seemed assured. The fleets and armies of the Byzantines had been decisively beaten by the Muslims and all the great cities of Persia had fallen to their arms. What Muawiya did not know however, was that the Byzantines had developed a new secret weapon.

Greek Fire as depicted in the Madrid Skylitzes
 This was a witch’s brew of all the flammable and sticky substances known to the Byzantines and its constituents most likely included sulphur, pine resin and crude oil sourced from the Caspian Sea region. The concoction was perfected in time to prove crucial to the defence of Constantinople from the attack of Muawiya’s fleet. Its precise make up has remained a matter of much speculation since this was the Byzantine Empire’s most closely guarded state secret which would guarantee centuries of naval supremacy. The man credited with its invention was one Kallinikos of Heliopolis; a Syrian Greek inventor who had rather fortuitously made his way to Constantinople in time to deliver the means for the city’s salvation. Greek fire had several properties which made it particularly effective in naval combat. Once alight, the burning liquid was impossible to extinguish with water and stuck to any surfaces it came into contact with such as ships’ hulls, rigging and the clothing of the unfortunate sailors. Being oil based it also floated upon the surface of the water, surrounding the enemy ship in a lake of fire. The liquid was stored on board ship in canisters which could be catapulted onto the decks of enemy vessels or dropped from cranes which swung out over the side if the ships were in close proximity; smashing on impact and requiring only a hurled ignition source to engulf the enemy in flames. Greek fire was at its most lethal when deployed using a siphon and the Chronicler Theophanes the Confessor tells us that the Byzantine fleet was well equipped with this apparatus. The most convincing modern reconstructions of what this might have comprised feature a pre-heating chamber in which the liquid was heated and pressurised by means of an air pump and a brazier before being forced out through a nozzle mounted in the bow of the ship and ignited by a flame positioned in front of the nozzle. The result was a terrifying eruption of flame against which there was no defence and from which there was no escape as the sea itself turned to fire around the doomed enemy vessel.

The Arab plan to take Constantinople was entirely dependent on a naval assault, which would overcome the Byzantine navy and then move in against the sea walls. Siege artillery had been mounted on the ships to allow them to batter their way into the city. In the event the Arabs simply had no answer to the destructive power of Greek fire and four successive expeditions mounted against Constantinople from 674 to 678 met with utter defeat and eventually the battered remains of the Arab fleet turned for home, only to be wrecked in a storm on the return journey; an event which further convinced the Byzantines that their city enjoyed divine protection. In the following year Muawiya renewed the peace treaty with Constantine IV, who had succeeded his father Constans. The Caliph gave up the recently conquered islands and resumed tribute, accepting for the time being that there was no way to overcome the great bastion city of Christendom, protected by its fire breathing ships.

Greek Fire had played a decisive role in the defence of the city of Constantinople in the face of the greatest threat to its existence that it had ever encountered. It would remain the most valuable weapon in the Byzantine armoury for centuries to come and would repeatedly safeguard the capital from attack. When the Arabs came against the city in force once more, it would again prove decisive.

In 717 the second great siege of Constantinople by the Arabs began. The Caliph Suleiman had amassed a fleet of over a thousand ships which sailed up the Marmara whilst the Caliph’s brother Maslama marched through Anatolia and then ferried his army across the Hellespont to invest the city from the landward side. Emperor Leo III immediately ordered an attack against the Arab fleet in which the power of Greek fire once more took a terrible toll on the Arab shipping and most of the supplies for the army were sunk to the bottom. The Arabs had no better answers to the problems of besieging Constantinople this time around than they had the last. The Theodosian Walls remained impregnable and they had nothing with which to counter the wonder weapon of Greek fire. Short of food, clothing and shelter, the besiegers endured a miserable winter outside the walls. When a second Arab fleet arrived from Egypt bringing much needed new supplies they anchored in a bay further down the coast in the hope of avoiding attack by the Byzantines. A mass desertion of Coptic Christian sailors who made a break for the city in the ships’ boats betrayed the presence of the fleet however and the fire breathing ships of Constantinople set out once more to inflict terror and destruction.

Failure of Second Siege of Constantinople from the Manasses Chronicle

The situation for the besiegers was looking hopeless. Theophanes, exercising his vivid imagination, delights in relating the depths of their privations. Once they had slaughtered every horse, ass and camel, he tells us, they were forced to knead the flesh of dead men and their own faeces together and eat it. Presumably as a result of these desperate culinary measures a terrible plague then swept through the Arab camp and carried off thousands. Still they did not heed the judgement of God and Theophanes has no hesitation in attributing the timely arrival of a Bulgar army which fell upon the wretched and starving Arabs to further divine assistance. This final calamity, Theophanes declares, at last convinced the besiegers of the futility of attacking Constantinople and they understood that the city enjoyed the protection of God. 

The death of Suleiman mercifully brought the expedition to an end as his cousin Umar who had succeeded him recalled the battered remains of the fleet and army. Theophanes rejoices further that many ships were wrecked in a storm on their way home in further evidence of God’s wrath. The city had survived the gravest threat to its existance in a century and would continue to resist all comers for centuries to come. There were to be no further large scale Arab attacks upon the city itself but others would try in their turn. That is a story for another day however.

Fantastic model reconstruction of Greek fire apparatus

First Siege of Constantinople

To continue the story go to

I was lazy for this article and reused material from my own book The Battles are the Best Bits, but if you liked it please check out the book. 

Tuesday, 12 March 2013

Rudolf Caracciola – The Original Meister

Well a new Grand Prix season is almost upon us and I for one am very excited. Many are asking whether anyone can stop the prodigiously talented German who has swept all before him over the past three seasons. This is, of course, a question that has been asked before in recent history but long before Vettel and Schumacher another German racer was regarded by many as the greatest of his generation.

Rudolf Caracciola 1901-1959

Rudolf Caracciola was born in Remagen in 1901. He began his career with Daimler-Benz as a humble car salesman but his passion was for racing cars rather than selling them. Thanks to his powers of persuasion he was able to secure modest support from his employers for his racing career and in 1926, by which time he was already a proven winner, he entered the inaugural Grand Prix of Germany at AVUS in a borrowed Mercedes M218 as a privateer. In spite of stalling on the opening lap and requiring a push start from his mechanic the 25 year old Caracciola nevertheless pulled off an incredible feat to fight his way through the forty four strong field in heavy rain to take the lead. Further drama ensued as Caracciola developed a miss-fire and was forced to pit for lengthy repairs. Back out on track he resumed his incredible progress and once more stormed into a lead he would hold until the end. With this remarkable victory Caracciola announced his arrival on the international racing scene and established a reputation for peerless driving in wet conditions.
Caracciola's 1926 German GP Win
Caracciola’s victory proved to be life changing in every way. With the prize money from the race he was able to set up his own business and also married his girlfriend Charlotte. He continued to race in hill climbs and road races, winning the inaugural race on the new Nurburgring but suffering mechanical failure in the 1927 German Grand Prix on the same circuit. He shared victory in the 1928 event in spite of pulling out of the race suffering from heat exhaustion as his team mate Christian Werner took over his car and continued on to win the race.

Caracciola remained a Mercedes stalwart, winning the European hill climbing championship in 1930 and competing in endurance racing. He competed at Le Mans and in the Mille Miglia thousand mile road race run on public roads between Rome and Brescia as well as continuing to win victories on the track.

By 1931 Mercedes had been forced to scale down their racing efforts in the face of global economic melt-down but they continued to support Caracciola and he did not disappoint; winning the German Grand Prix against the superior Bugattis of Louis Chiron and Achille Varzi by over a minute when the elements once more presented him with an opportunity to demonstrate his unrivalled ability to keep a racing car on track in the wet. Caracciola also triumphed in the 1931 Mille Miglia, becoming along with co-driver Wilhelm Sebastian the first non-Italian winners of the event. Driving his Mercedes SSKL at an average speed of 101km/h Caracciola won the race in record time.

Caracciola/Sebastian 1931 Mille Miglia

The Italians took note and with the complete withdrawal of Mercedes Benz from racing in 1932 Caracciola was snapped up by Alfa Romeo although he would compete initially as a semi-independent and with inferior machinery to the leading Italian drivers. After a number of impressive performances however Caracciola was offered a place within the works team and went on to win four Grands Prix for Alfa Romeo that year including another German Grand Prix victory.

In the following year Alfa Romeo too felt the pinch and withdrew from racing, leaving Caracciola without a contract. Undaunted, he set out as a privateer outfit again; racing customer Alfas along with his friend Louis Chiron. In practice for the Monaco Grand Prix however, Caracciola suffered a serious accident, slamming into a wall at the Tabac corner and shattering his femur. As he was carried from the wreckage a bystander reassured Caracciola that Monte Carlo had an excellent hospital and that many famous people had died there. It would take him a year to recover and he would be left with a limp for the rest of his life. Further tragedy struck him during his recuperation in Switzerland when his wife Charlotte was killed in an avalanche whilst skiing, plunging Caracciola into deep despair.

The rise of the Nazis breathed new life into the sporting programmes of Mercedes Benz and their rivals Auto Union as the party willingly poured funds into motorsport as an ideal theatre to showcase German engineering and sporting prowess on the international stage and Caracciola was persuaded to return to racing and public life. For the sake of their careers Caracciola and his German contemporaries were obliged to join the NSKK; the Nazi party’s motorsport wing, although Caracciola never joined the Nazi party itself.

In 1934 Caracciola was back in a works Mercedes Benz although he struggled at times with the pain from his leg injury and a second place finish in the Spanish Grand Prix was his best result on the track.

Caracciola 1935 Tripoli GP
In the following year however the German was back to his very best at the Tripoli Grand Prix which was a heavily wagered-upon race with starting grid positions being decided by lottery. The race was run to Formula Libre regulations and was not part of the more tightly regulated European Drivers Championship; forerunner of today’s World Championship. Caracciola drove a canny race on the rough and dusty desert track. Recovering from an early puncture just five laps into the race, Caracciola combined a blistering pace; at times lapping ten seconds a lap faster than his rivals, with an ability to look after his tyres that his modern equivalents would appreciate, to find himself in the lead when the Alfas of Nuvolari and Varzi struggled with tyre wear towards the end of the race.

The European Drivers Championship for 1935 comprised five races of which Caracciola in his Mercedes W25 won three. In the penultimate event, the Spanish Grand Prix, Caracciola was required to start from the back of the grid as starting places were decided by lottery. By the first corner he was in the lead having mistaken the throttle for the brake pedal but somehow still made it around the turn and went on to win both the race and the championship.

In 1936 the European title went to Caracciola’s friend and rival Bernd Rosemeyer who drove for Auto Union although Caracciola banished his Monaco demons by winning the race. Caracciola went on to win a further two European championships in 1937 and 1938; being the only driver to achieve this feat. In 1937 he also married his second wife Alice.

As the rivalry between Mercedes Benz and Auto Union intensified, their battle embraced the quest for the world land speed record. On January 28th 1938 on a stretch of newly constructed autobahn between Frankfurt and Darmstadt the two manufacturers set out to fight head to head for the record. Rudolf Caracciola made his attempt first, driving a stream-lined Mercedes W125 at a speed of 268.9 mph (432.7km/h) over a measured kilometre; setting a record for speed on a public road which stands to this day. It was a bitter-sweet achievement however for Rosemeyer was killed attempting to beat the record for Auto Union when cross-winds swept his car into a deadly somersault. The death of his friend caused Caracciola to question the value and purpose of a racer’s life but in the end he fatalistically accepted that the risk-taking Rosemeyer had inevitably run out of luck.

Rosemeyer prior to fatal 1938 world speed record attempt

The advent of the Second World War brought such trivial pursuits to an end. Caracciola sat the war out in Switzerland and made plans to race in America at the war’s end. In 1946 he travelled to America and entered the Indianapolis 500 in a borrowed car, unfortunately hitting the wall during practice for the race in an accident which left him in a coma for several days.

In 1952 he made a return to racing in Europe, competing once more in the Mille Miglia but a crash in the Swiss Grand Prix of that year in which he hit a tree and suffered a serious fracture, this time in his other leg, proved to be a career-ending injury. Caracciola continued to work for Mercedes Benz, resuming his sales role and making use of his celebrity status. Sadly his health deteriorated rapidly and he died from liver failure in 1959, aged just 58.

He is remembered as one of the most talented and accomplished drivers of his own, or any generation; a three times European Grand Prix champion and a three times European hill climb champion; the fastest man on four wheels over a single mile or over a thousand miles, peerless in the rain and indomitable in the desert. A six time winner of the German Grand Prix; Rudolf Caracciola quite simply was the master.

Caracciola’s first Grand Prix victory

Caracciola wins in Tripoli

Caracciola and the land speed record

Caracciola wins the Mille Miglia

Tuesday, 5 March 2013

By Jove - The Story of Jupiter

On a crisp winter’s evening a few days after Christmas, my wife Adele and I carefully carried my new telescope outside into the back garden. After a few trips back and forth to the house to fetch hats and gloves and a torch we were ready to take our first tottering steps into the world of astronomy.

After a little trial and error, peering through the star pointer and twiddling the declination and right ascension knobs, we at last experienced a sudden eureka moment as the planet Jupiter all at once came into focus. Big and bright in the centre of the eyepiece there it was, with its dark bands of raging clouds clearly visible. We were very chuffed indeed. A few nights ago (at time of writing) I was even more excited when I once more brought the planet into focus and was able to observe all four of its moons.

It was exciting enough for me. Just imagine therefore how chuffed another keen astronomer was one night in January 1610 when he pointed his new telescope skywards to investigate that same bright spot in the heavens and beheld for the first time through such an instrument the shining disc of Jupiter.

Galileo Galilei had already had some success with his shiny new toy which he had fashioned himself following a recently patented Dutch design rather than purchasing it from the internet as I had done. After carrying out observations of the lunar surface, Galileo turned his attention to Jupiter and was soon intrigued by the fact that the three stars around the planet were changing their positions relative to Jupiter and each other on a nightly basis. Galileo conducted nightly observations of Jupiter over the next eight weeks, during which he sketched the position of these Medician Stars as he had dubbed them in honour of his patron Cosimo di Medici. As he traced the movements of these bodies, which he observed did not twinkle like other stars, Galileo was able to conclude that there were in fact four rather than three of them and that they were orbiting around the planet Jupiter. This was a remarkable revelation, for it leant great weight to the highly inflammatory theory of Copernicus which proposed that the planets circled around the sun rather than the Aristotelian position favoured by the Catholic Church which maintained that the earth itself was the centre of the universe.

Galileo demonstrates a telescope to the Doge of Venice

Galileo published his findings in his treatise Sidereus Nuncius. His work was immediately seized upon with great enthusiasm by one Johannes Kepler, who was at that time Imperial Mathematician at the university of Prague. Kepler was a keen adherant of Copernicus' theory and having obtained a telescope of his own soon published a response to Galileo supporting his findings. All at once the universe had been shown to possess not a single point around which all other heavenly bodies rotated but at least two. The earth-centric Aristotelian viewpoint  had been shaken to the core.

Various unsatisfactory naming systems were put forward for the newly discovered satellites of Jupiter but it was Kepler who proposed the pleasing classical monikers that stuck. The moons of Jupiter, drawn irresistibly towards it as they were, Kepler suggested should be named after that notoriously seductive god’s best known sexual conquests: Io, Calisto and Europa. The fourth he proposed should be named Ganymede; after the young shepherd boy who was borne aloft by an eagle to serve as cup bearer to the greatest of the Gods.

Like Galileo, Kepler later suffered for his beliefs. He was hounded from his University position in 1626 as a result of his Protestant faith and his mother was even tried as a witch. One can only imagine how a man at the forefront of the enlightenment felt when faced with such barbarous superstition.

The best known of Jupiter’s landmarks is of course its great red spot. This remarkable surface feature; a giant storm the size of three earths, was first observed by English polymath and Royal Society founding member Robert Hooke in 1664. Hooke noted that the position of the spot changed over the course of several hours, leading him to conclude that the planet was rotating on its axis.
Proceedings of the Royal Society 1664
Also taking an interest in the progress of the red spot was Gian Domenico Cassini in Bologna. By tracking the spot's movements Cassini was able in 1665 to calculate Jupiter’s rotation period at 9hrs and 56 minutes. Cassini also studied the movements of Jupiter’s moons and was puzzled by the refusal of their orbits to conform to his predictions. In 1676 the eminent scholar, now based in Paris, found himself upstaged by his brilliant young pupil Olaus Roemer who proposed that the reason for the apparent variability in the orbit of Jupiter’s moons was due to the varying distance between Earth and Jupiter at different times according to their respective orbits. Because light travels at a finite speed, Roemer suggested, the light from the moons would sometimes take longer to reach the earth. Cassini dismissed the suggestion but Roemer was proved right when he correctly predicted that on a given date the moon Io would emerge from behind Jupiter ten minutes later than Cassini’s model suggested that it should. There was in fact nothing wrong with Cassini’s reckoning but due to the increased distance between the two planets, the moon was not visible at the time that it emerged as the light reflected from it took longer to reach the earth.

Gian Domenico Cassini
So there you have it. From the mere process of gazing up at a distant planet in the heavens and observing the movements of its surface features and moons, far greater minds than mine had deduced that the planets revolved around the sun, that Jupiter revolved upon its axis in a little under ten hours and that light travelled at a finite speed. By contrast I had merely pointed my telescope in the right direction, gawped up at the planet and been very pleased with myself at having observed it at all. Ah well, we can’t all be geniuses can we?

Galileo's observations of Jupiter's moons

The Great Red Spot

 Cassini, Roemer and the Speed of Light