Loudon's posts at Schlukenau, Rumberg, and Gabelona were taken by the prince, who forced him to abandon Aussig and Dux, with the fortifications and magazine at Leutmeritz, and, indeed, all the left bank of the Elbe; but falling back on the Iser, he skilfully secured its passages by strong detachments. In short, so equal was the distribution of strength, numbers, skill, and discipline, that the war was a mere succession of able movements, but barren of striking events; and after a year of marches and skirmishes, the Emperor relinquished Lower Bavaria, on which he had seized unjustly, and a peace was concluded on the 13th May, 1779, the birthday of the Empress-Queen. After this Loudon returned to his sequestered castle; and once more, for eight years, resumed the peace and pleasure of a country life. In 1787, when in his seventy-first year, he was again summoned to the field by the Emperor, to lead the Austrian armies against the Turks; and a series of brilliant captures and encounters realized all that had been hoped from his old valour and experience. He poured his hosts along the Croatian and the Bosnian frontiers; and in August, 1788, after two fruitless assaults, in one of which 430 of his men were killed and wounded, he received by capitulation the fortress of Dubitzar, on the right bank of the Unna. On the 20th the Turks had attacked his camp, but were repulsed; after which he again ordered an immediate assault; but, as it failed, he ordered the town to be fired, and it burned till the morning of the 24th. He then opened several mines, and by the 25th his sappers were within ten feet of the walls. The Turks then "capitulated to Marshal Loudon, whose principal terms were:-- "That the officers might march out with swords, but their troops were to lay down all arms and surrender as prisoners of war. "That the women and children might go to Roczaracz, attended by five Turkish soldiers, for whose return the commandant should be answerable." Novi-bazar, a Bosnian Sanjak, the capital of a province, with its castle, next fell into his possession; then Gradiska, a strong Turkish fortress which had been erected fifteen years before by French engineers, at the junction of the Virbas with the Saave; then Belgrade, the most important town and fortress on the Austrian frontier of the Turkish empire. Its citadel occupies a commanding position on the summit of a precipitous rock which rises in the centre of the streets and is surrounded by a lofty wall, a triple fosse with flanking towers, and an esplanade 400 paces broad. These works were principally constructed by Benjamin Swinburne, a native of Staffordshire, who had embraced Islamism, adopted the name of Mustapha, and risen to high rank in the Turkish artillery. Led on by Loudon, the Austrians overcame every obstacle, and captured this famous Belgrade.