While the greater part of the Prussian troops marched to Bohemia, where they defeated the Austrian and Saxon troops on 3 July 1866 at Königgrätz (Sadova), another part of the Prussian troops invaded the Kingdom of Hanover. After the surrender of Hanover on June 29 these troops - including some small units of allies of Prussia - were grouped under the name "Mainarmee" (German for: Army of the Main) and pushed southward towards the river Main against the South-German allies of Austria.