treaty with Charles. Habsburg Netherlands would only be able to incorporate Guelders and Zutphen under Charles V. Following Margaret's strategy of defending the Low Countries with foreign armies, in 1513, at the head of Henry VIII's army, Maximilian gained a victory against the French at the Battle of the Spurs, at little cost to himself or his daughter (in fact according to Margaret, the Low Countries got a profit of one million of gold from supplying the English army). For the sake of his grandson Charles's Burgundian lands, he ordered Thérouanne's walls to be demolished (the stronghold had often served as a backdoor for French interference in the Low Countries). Reign in the Holy Roman Empire Recapture of Austria and expedition to Hungary Maximilian was elected King of the Romans on 16 February 1486 in Frankfurt-am-Main at his father's initiative and crowned on 9 April 1486 in Aachen. Much of the Austrian territories and Vienna were under the rule of King Matthias Corvinus of Hungary, as a result of the Austrian–Hungarian War (1477–1488). Maximilian was now a king without lands. Matthias Corvinus offered Emperor Frederick and his son prince Maximilian, the return of Austrian provinces and Vienna, if they would renounce the treaty of 1463 and accept Matthias as Frederick's designated heir and favoured successor as Holy Roman Emperor. Before this was settled though, Matthias died in Vienna in 1490. However, after Matthias Corvinus died from a stroke on 6 April 1490, civil war broke out in Hungary between the supporters of John Corvinus and the supporters of king Vladislaus of Bohemia. Due to the Hungarian civil war, new possibilities were opened for Maximilan. From July 1490, Maximilian began a series of short sieges that reconquered cities and fortresses that his father had lost in Austria. Maximilian entered Vienna without siege, already evacuated by the Hungarians, in August 1490. He was injured while attacking the citadel guarded by a garrison of 400 Hungarians troops who twice repelled his forces, but after some days they surrendered. With money from Innsbruck and southern German towns, he raised enough cavalry and Landsknechte to campaign into Hungary itself. Despite Hungary's lower nobility, the gentry's hostility to the Habsburg, he managed to gain many supporters from higher aristocracy, including several of Corvinus's former supporters. One of them, Jakob Székely, handed over the Styrian castles to him. He claimed his status as King of Hungary, demanding