Battle of Trautenau The Battle of Trautenau ( ) or Battle of Trutnov was fought on June 27 , 1866 , during the Austro - Prussian War . It was the only battle of the war that ended in an Austrian victory over the Prussians , but at a large cost . Background . The Prussian Second Army invading Bohemia had to split up in order to negotiate the difficult passes of the Giant Mountains . As they emerged on the Bohemian side , they met Austrian forces . At Nachod the Austrians were soundly beaten , but on the same day , as Generalfeldmarschall Adolf von Bonin ’ s I Corps emerged from the passes it was caught in the open on its way through Trautenau towards Pilníkov , where it was hoped to link up with the First Army . The Battle . Bonin ' s vanguard cleared the passes during the late morning and entered Trautenau at 10 : 00 . The Austrian X Corps , lead by Ludwig von Gablenz , had broken camp at 8 : 00 and marched towards Trautenau to stop Bonin ' s advance . The Austrian troops arrived piecemeal with the Mondel brigade – which had started its march before the bulk of the Corps – being in position on the heights behind Trautenau at 7 : 45 . The advance guard of the Prussians was attacked by skirmishing Austrian Jäger when resting in the town square . Mondel , who had been ordered to avoid a general engagement until the whole Corps had assembled , pulled back his troops to the heights . Mondel ' s rear guard managed to hold up the Prussians until noon . By 12 : 00 Bonin ' s 1st division had driven of Mondel and pushed up to the town of Neu - Rognitz , his 2nd division had taken the heights and was scouting in the direction of the town of Alt - Rognitz . This gave the Prussians the time to move troops and guns up the commanding heights . As the Austrian brigades started arriving , Gablenz ordered a second brigade ( Wimpffen ) to pass Mondel and take the Johannesberg , while a third brigade ( Grivicic ) was to envelop the Prussian left and storm the Hopfenberg . To prepare the attack , Gablenz ordered a grand battery of 40 guns to open up fire on the Prussian held heights . Upon this heavy bombardment Bonin panicked and started to withdraw back towards the passes . Before this retreat could be enacted , the Austrians attacked in half - battalion masses . The Austrian attacks of Grivicic and Wimpffen were uncoordinated and stalled against the Prussian fire from the Dreyse needle gun . Four Prussian battalions from the rear guard thus managed to hold up the Austrian brigades . By 5PM Gablenz fourth briagde ( Knebel ) had arrived and was originally placed in reserve . When he saw Grivicic ' s and Wimpffen ' s brigades struggling , Knebel disregarded orders and attacked and took the heights in conjunction with Wimpffen , losing 900 men in the process , to drive of Bonin ' s rear guard . Outcome . Although an Austrian victory , the cost had been high . The Austrians lost about 5000 men to the Prussians 1400 . Although the Prussian I Corps had been driven back , Glabenz position had become untenable . To his left Steinmetz ' s V Corps had broken through at Nachod and to his right the Prussian Guard Corps was nearing Eipel , threatening both his flanks . The following day Gablenz tried to evade encirclement by the Prussian Guards but he had to sacrifice most of his Grivicic brigade , which was nearly destroyed at Burkersdorf and Rudersdorf , to enable his retreat .