Upon Gian Gastone's death on 9 July 1737, Francis Stephen ceded Lorraine and became Grand Duke of Tuscany. In 1738, Charles VI sent the young couple to make their formal entry into Tuscany. A triumphal arch was erected at the Porta Galla in celebration, where it remains today. Their stay in Florence was brief. Charles VI soon recalled them, as he feared he might die while his heiress was miles away in Tuscany. In the summer of 1738, Austria suffered defeats during the ongoing Russo-Turkish War. The Turks reversed Austrian gains in Serbia, Wallachia and Bosnia. The Viennese rioted at the cost of the war. Francis Stephen was popularly despised, as he was thought to be a cowardly French spy. The war was concluded the next year with the Treaty of Belgrade.