The battle of Hammelburg (10 July 1866) was one of two defeats suffered by the Bavarians on the same day, as they retreated south in the aftermath of a failure to join up with their German allies (Austro-Prussian War, 1866).
At the start of the war the Prussians were faced with three opponents in Germany - the Hanoverian Armies in the north, the 8th Federal Corps around Frankfurt and the Bavarian Army at Bamberg. The Prussians had three divisions, commanded by Marshal Falckenstein. Their first objective was to eliminate the Hanoverians, and despite a defeat at Langensalza on 27 June, they quickly achieved this. The Hanoverians were surrounded and forced to surrender on 29 June.
While this fighting was going on, 8th Corps and the Bavarians were still trying to decide what to do. They eventually decided to unite north of the Hohe-Rhön Mountains, with the main move to begin on 30 June. This was too late. By the time the Bavarians reached the northern end of the mountains, the Prussians were already there. On 4 July the Prussians defeated the Bavarians in two separate engagements (battle of Dermbach, 4 July 1866).
In the aftermath of the defeats on 4 July the two German forces retreated away from each other. The Federal 8th Corps retreated south-west back towards Frankfurt, while the Bavarians retreated south towards the Saale River.
At first the Prussians moved down the western side of the mountains, apparently following the 8th Corps. By the end of 8 July Goeben's and Beyer's Divisions had moved south of Fulda - Beyer was on the road that ran south-west towards Frankfurt, Goeben on a road that ran south-east across the mountains to Brückenau. Manteuffel's division reached Fulda. On 9 July the Germans turned east. Beyer moved to the baths of Brückenau, west of the town. Manteuffel reached the town of Brückenau. Goeben's division moved further, reaching Geroda. On the road that led to Kissingen.
Falckenstein's plan was to concentrate against the Bavarians. The advance past Fulda was meant to mislead them, and it succeeded. By the end of 9 July the Bavarians were spread out along a narrow line 22 miles long. Their left was at Hammelburg, where there was one brigade from Zoller's division. Another of Zoller's brigades was posted at Kissingen. Feder's division was further to the north-east at Münnerstadt. Hartmann's division was just to the south. Stephan's division and the army HQ was at the northern (right) end of the line at Neustadt. The Bavarians expected any Prussian attack to come from the north.
The village was defended by Schweitzer's 6th Brigade, with 11 guns and a small force of cavalry. His advance guard was posted at the village of Unter-Erthal, on the north western side of the River Thulba, which flows south to flow into the Saale. Hammelburg is on the north bank of the Saale, east of the junction with the Thulba.
At about 10am the advance guard of Beyer's Division, commanded by General von Schachtmeyer, encountered some Bavarian cavalry around Neu-Wirthshaus. They then found the Bavarian advance guard, which was posted just south of Unter-Erthal. Schachtmeyer moved a battery of 4-pounder guns onto a hill west of the village and open fired. The Bavarians responded with fire from two rifled guns posted east of the Thulba, but these were soon withdrawn. In the meantime the Bavarian advance guard retreated back across the Thulba, and then skirted around Hammelburg and crossed the Saale a little further to the east, at Fuchsstadt.
General Schachtmeyer left one battalion to guard Unter-Erthal and then advanced along the road towards Hammelburg. His leading troops pushed the Bavarians away from the bridge over the Thulba, and the Prussians moved onto the eastern bank of the river. The Prussians quickly captured some hills north of the town, and moved the advanced guard battery into place. This triggered an artillery duel with two Bavarian batteries on the opposite side of the Saale, which was carried on for some time with little result.
By this point Generals Falckenstein and Beyer had reached the front. The hilly terrain meant that they couldn't be sure how many Bavarians were in the area, and so Falckenstein ordered Beyer not to attack until the rest of his division had arrived. He also sent a message to General Goeben to ask him to send help if he wasn't already engaged. By this point General Goeben was indeed heavily engaged at Kissingen, and was unable to respond.
Once the main Prussian forces had arrived, General Falckenstein ordered the attack. Beyer decided to begin with an attack on the Offenthaler Berg, a key hill overlooking the town from the north-east. This was only defended by a single Bavarian battalion, and this withdrew in the face of the overwhelming Prussian attack.
The Prussians took advantage of this and followed the retreating Bavarians closely. Their momentum brought them into the outskirts of Hammelburg, and the remaining Bavarian troops retreated south across the Saale. The town was entirely in Prussian hands by 3pm.
Just before the town fell news had arrived of Goeben's more serious battle at Kissingen. Falckenstein ordered Beyer to concentrate his division at Hammelburg, and then moved north to Kissingen.
Both sides suffered similar losses at Hammelburg. The Prussians lost 10 dead and 72 wounded. The Bavarians lost 7 dead, 42 wounded and 15 missing or prisoners.
In the aftermath of their two defeats at Hammelburg and Kissingen the Bavarians retreated south in some confusion. They were saved from further fighting by events in Austria, where peace negotiations were getting underway. Bismarck wanted the Prussians to occupy Frankfurt and the area north of the Main before the fighting ended, and ordered General Falckenstein to turn west to defeat the 8th Federal Corps.