the real bulwark with a wall seven kilometres long. Today the ivy-clad remains still bear witness to its stony force. Adorned with arrow slits and battlements, further protected by moats, guarded by mighty square towers, in double and triple parallel rows completed and renovated again and again by every emperor over 1,000 years, this majestic wall encircling the city is regarded as the emblem of impregnability of its time. Like the unbridled storm of the barbarian hordes in the past, and the warlike troops of the Turks now in the days of Mahomet, these blocks of dressed stone still mock all the engines of war so far invented; the impact of battering rams is powerless against them, and even shots from the new slings and mortars bounce off the upright wall. No city in Europe is better and more strongly defended than Constantinople by its Theodosian walls.
Mahomet knows those walls and their strength better than anyone. A single idea has occupied his mind for months and years, on night watches and in his dreams: how to take these impregnable defences, how to wreck structures that defy ruin. Drawings are piled high on his desk, showing plans of the enemy fortifications and their extent; he knows every rise in the ground inside and outside the walls, every hollow, every watercourse, and his engineers have thought out every detail with him. But he is disappointed: they all calculate that the Theodosian walls cannot be breached by any artillery yet in use.
Then stronger cannon must be made! Longer, with a greater range and more powerful shots than the art of war yet knows! And other projectiles of harder stone must be devised, heavier, more crushing, more destructive than the cannonballs of the present! A new artillery must be invented to batter those unapproachable walls, there is no other solution , and Mahomet declares himself determined to create this new means of attack at any price.
At any price… such an announcement already arouses, of itself, creative driving forces. And so, soon after the declaration of war, the man regarded as the most ingenious and experienced cannon-founder in the world comes to see the Sultan, Urbas or Orbas, a Hungarian. It is true that he is a Christian, and has already offered his services to Emperor Constantine; but, rightly expecting to get better payment for his art, and bolder opportunities to try it, he says he is ready, if unlimited means are put at his disposal, to cast a cannon for Mahomet larger than any yet seen on earth. The Sultan, to whom, as to anyone possessed by a single idea, no financial price is too high, immediately gives him as many labourers as he wants, and ore is brought to Adrianople in 1,000 carts; for three months the cannon-founder, with endless care, prepares and hardens a clay mould according to secret methods, before the exciting moment when the red-hot metal is poured in. The work succeeds. The huge tube, the greatest ever seen, is struck out of the mould and cooled, but before the first trial shot is fired Mahomet sends criers all over the city to warn pregnant women. When the muzzle, with a lightning flash, spews out the mighty stone ball to a sound like thunder andwrecks the wall that is its target with a single shot, Mahomet immediately orders an entire battery of such guns to be made to the same gigantic proportions.
The first great “stone-throwing engine”, as the Greek scribes in alarm called this cannon, had now been successfully built. But there was an even greater problem: how to drag that monster of a metal dragon through the whole of Thrace to the walls of Byzantium? An odyssey unlike any other begins. A whole nation, an entire army, spends two months hauling this rigid, long-necked artefact along. Troops of horsemen in constant patrols thunder ahead of it to protect the precious thing from any accident; behind them, hundreds or maybe thousands of labourers work with carts to remove any unevenness in the path of the immensely heavy gun, which churns