The combat of Huhnerwasser (26 June 1866) was the first clash between Austrian troops and the Prussian Army of the Elbe at the start of the Prussian invasion of Bohemia (Austro-Prussian War).
At the start of the war the Prussians had three armies ready to attack Austria. On their right (western) flank was the Army of the Elbe under General Karl E. Herwarth von Bittenfeld. This army had the task of invading Saxony, one of Austria's many German allies during the war. The Army of the Elbe crossed into Saxony on 16 June, and occupied Dresden on 18 June. The Saxon army put up no resistance and instead retreated to join up with the main Austrian army. The Prussians had overrun all of Saxony by 20 June. The Army of the Elbe then advanced across Saxony towards the Austrian border, ready for the next stage of the war - the invasion of Austrian Bohemia.
The Army of the Elbe and the Prussian 1st Army (Prince Frederick Charles) crossed the Austrian border on 23 June, heading towards each other and the Iser River. The 1st Army began the march some way to the east of the Army of the Elbe, but they rapidly closed in on each other.
On 26 June the Army of the Elbe had orders to reach Niemes and Oschitz, south-west of Gabel. The advance guard was sent south from Niemes, and eventually ran into an outlying Austrian force, Leiningen's brigade, which was posted near Hühnerwasser. At this point the main Austrian force in the area, General Clam-Gallas's I Corps, was concentrating at Münchengrätz, on the east bank of the Iser, and south-east of Hühnerwasser.
During the advance the Prussian advance guard ran into some Austrian cavalry at Hühnerwasser. The Prussians forced the Austrians back into some woods, which were defended by Leiningen's Brigade. At 11.00am General Schöler attacked the Austrian position, and the Austrian infantry retreated.
That ended the fighting for most of the day, but at around 6pm there was a fresh outburst of fighting, variously described as a counterattack or a skirmish with an Austrian jäger battalion. This attack was also repulsed. Typically of just about every clash during this war, the Prussians suffered lighter losses than the Austrians, with the credit normally going to the Prussian needle gun. The Prussians lost 7 dead and 43 wounded during the day's action. The Austrians lost 277 killed, wounded and missing.
To the north-east the 1st Army had also run into Austrian troops. The combat of Liebenau saw the Austrians pushed back from their outlying positions north of the Iser. They had then abandoned the town of Turnau, on the Iser, allowing the Prussians to occupy it unopposed. This gave them a foothold on the east bank of the river. That evening the Austrians attempted to counterattack, but they were defeated well to the south of Turnau (combat of Podol, 26-27 June 1866). The Prussians now had control of a long stretch of the Iser, and the Army of the Elbe and the 1st Army were firmly in touch with each other.
Crown Prince Albert of Saxony, commander of the Austrian and Saxon forces on the Iser, realised that his troops were in danger of being isolated. They spent 27 June preparing to retreat east to Gitschin, while the Prussians spent the day preparing for a full scale attack on Münchengrätz.