Though the Scheldt became a French river in 1797, after the Treaty of Campo Formio, and though the Convention of The Hague had already abolished the shipping dues, Antwerp had made no progress towards recovery when Napoleon went there in 1803. He deepened the harbour, strengthened the fortifications, expended immense sums on improving the communications with Amsterdam and other places in the Netherlands, and purposed making the great seaport opposite the mouth of the Thames his chief naval station. He even planned the building of a new city. England was equally aware of the value of Antwerp. The Walcheren expedition, that costly failure,[56] was undertaken to strike a blow at this vital spot; and the Conference of Chatillon, in 1814, broke down because Napoleon would not relinquish Antwerp. He could not make up his mind to let it go. Long afterwards he said: 'Antwerp was to me a province in itself. It was the principal cause of my exile to St. Helena; for it was the required cession of that fortress which made me refuse the terms offered at Chatillon. If they would have left it to me, peace would have been concluded.' And it was still in his possession when the end came. Carnot was there--'iron Carnot, far-planning, imperturbable'--and held the fortress till the Emperor abdicated. Trade revived with the creation of the Kingdom of the Netherlands. By 1830 the population had increased to between 70,000 and 80,000. There was a strong Orange party in the city during the Belgian Revolution, for the Scheldt is to Antwerp what the Nile is to Egypt--its life; and the union with Holland insured the freedom of the river. Antwerp, however, suffered more at that time from the Dutch than Brussels. General Chassé, an old soldier of the Empire, who had lived there for some years, was in command of the troops in the citadel.[57] He had under him between 2,000 and 3,000 men. The forts and ramparts were armed with nearly 300 heavy guns, and in the Scheldt, close to the town, were nine ships of war. An exchange of shots between some of the Belgian insurgents and the Dutch was followed by a furious bombardment. For seven hours the citadel, the forts on the other side of the river, and the ships continued their fire. The houses shook with the noise of the big guns and the rattle of musketry. The terror and confusion were indescribable in the streets, which were lighted up, after darkness fell, by the flames roaring from the Church of St. Michael, which was burned to the ground. A great deal of damage was done, but fortunately the ships were so close to the shore that their shot passed over the housetops, otherwise the whole of Antwerp might have been destroyed. The spire of the Cathedral was a conspicuous object, rising high above the Place Verte in the most crowded part of the town. The shells flew past it and over it, but only three did any harm, one bringing down a turret, and two crashing through the roof and bursting in the nave.