immediately due to his father's unwillingness to provoke the emperor. Edict of Restitution In March 1629, Emperor Ferdinand II passed the Edict of Restitution. It was specifically aimed at restoring the situation of the 1555 Peace of Augsburg in ecclesiastical territories that had since strayed from "legal" Catholic faith and rule. Bremen and Magdeburg were the biggest examples of territories to be restituted. Alliance with the Swedish king The city's councillors had been emboldened by King Gustavus Adolphus's landing in Pomerania on 6 July 1630. The Swedish king was a Lutheran Christian, and many of Magdeburg's residents were convinced that he would aid them in their struggle against the Roman Catholic Habsburg emperor, Ferdinand II. However, not all Protestant princes of the Holy Roman Empire had immediately embraced Adolphus; some believed his chief motive for entering the war was to take northern German ports, which would allow him to control commerce in the Baltic Sea. In November 1630, King Gustavus sent ex-Administrator Christian William back to Magdeburg, along with Dietrich von Falkenberg to direct the city's military affairs. Backed by the Lutheran clergy, Falkenberg had the suburbs fortified and additional troops recruited. Magdeburg besieged When the Magdeburg citizens refused to pay a tribute demanded by the emperor, Imperial forces under the command of a Flemish mercenary, Johann Tserclaes, Count of Tilly laid siege to the city within a matter of months. The city was besieged from 20 March 1631 and Tilly put his subordinate Imperial Field Marshal , a Catholic convert, in command while he campaigned elsewhere. During fierce fighting, Imperial troops numbering 24,000, roughly the same number as Magdeburg's entire population, conquered several sconces of the city's fortification and Tilly demanded capitulation. Assault and sacking After two months of siege and despite the Swedish victory in the Battle of on 13 April 1631, Pappenheim finally convinced Tilly, who had brought reinforcements, to storm the city on 20 May with 40,000 men under the personal command of Pappenheim. The Magdeburg citizens had hoped in vain for a Swedish relief attack. On the last day of the siege, the councillors decided it was time to sue for peace, but word of their decision did not reach Tilly in time. In the early morning of 20 May, the attack began with heavy artillery fire. Soon afterward, Pappenheim and Tilly launched infantry attacks. The fortifications were breached and Imperial forces were able to