The cause of the war for Austrian succession were Prussia's claims to the possessions of the Austrian Habsburgs, which upon the death of Emperor Charles IV passed to his daughter Maria Theresa, as there was no direct male heir. The Prussian king refused to recognize the rights of Maria Theresa and in 1740 captured Silesia, an Austrian province. Prussian King Frederick II gained the support of Bavaria and France. England participated on the side of Austria. After an agreement concluded between Austria and Russia in 1746, the positions of the anti-Prussian coalition were greatly reinforced, which brought the war to a speedy end. Maria Theresa kept the crown, though Silesia remained in the hands of Frederick.