Kingdom of Saxony
During the 1866 Austro-Prussian War, Saxony sided with Austria.  The Saxon army was the only large army to help Austria.  At the peace talks Austria said Saxony should not be punished.  The  other states in north Germany including the large Kingdom of Hanover were annexed (taken over) by Prussia after the war.  These states had promised help to Austria but did little, so Austria did not try to help them at the peace talks.