The Prussian I Corps was 
emerging from the mountains at 
Trautenau as the battle at 
Nachod was winding down.  
Located some twenty miles to the 
north of Nachod, Trautenau - 
unbeknownst to the Prussians - 
was an Austrian strongpoint.

As they passed the city on June 
27, 1866, Austrian troops from 
X Korps' leading brigade began 
firing from the hills south of 
town.  Quickly forming his 
troops, I Corps commander 
General Eduard von Bonin forced 
the Austrians off the hills 
with heavy losses, pursuing 
them south nearly to Hohenbruck.
Assuming that he'd won the 
battle, Bonin resumed his march 
to the west, again neglecting 
to secure the hills south of 
Trautenau.

As the Prussians moved back 
north, the Austrians again 
attacked.  Pinning I Corps from 
the south with infantry assaults
from three brigades, X Korps 
commander Lt. Field Marshal 
Ludwig von Gablenz brought his 
4th brigade around the Prussian 
lines to strike their flank.  
Despite doing massive damage 
with their Needle-guns, the 
Prussians' poor communications 
hampered I Corps' response, and 
the defeat turned quickly into 
a rout. 

The Prussian I Corps fell back 
as far as 25 miles, and was 
replaced as the lead formation 
the next day by the Prussian 
Guards Corps.  Gablenz withdrew 
the Austrian X Korps to Soor, 
to await another Prussian 
attempt to force the pass.