 Complete the following phrase:  On 10 April 1809 Austrian forces under Archduke Charles crossed the border of Bavaria, a French client state. The French response, under Louis-Alexandre Berthier, was disorganised but order was imposed with the arrival of Napoleon on 17 April. Napoleon led an advance to Landshut, hoping to cut off the Austrian line of retreat and sweep into their rear. Charles crossed the Danube at Regensburg, which allowed him to retreat eastwards, though he failed to reach the Austrian capital, Vienna, before the French. A French assault across the Danube was repulsed on 2122 May at the Battle of Aspern-Essling but a repeat attack was successful in July. Napoleon won a major victory at the 56 July Battle of Wagram, which forced the Austrians to sign the Armistice of Znaim on 12 July. Austrian invasions of the Duchy of Warsaw and Saxony where they fought alongside the Black Brunswickers were repulsed and they were driven out of their territories in Italy. British forces 