The battle of Fehrbellin saw Frederic William, elector of Brandenburg and duke of Prussia defeat a Swedish army under Karl Gustav Wrangel that had invaded Brandenburg late in 1674 (Scania War). Frederick William had responded to the invasion with something of a scorched earth policy, removing all food from the areas the Swedes were marching through, and ordering his people to avoid all contact with the invaders. This policy worked, and by May 1676 Wrangel reported that his men were complaining about a lack of bread. This forced him to divide his army, which at the start of the invasion had been only 13,000 men strong. In June 1675 he was west of Berlin, with most of his army at Alt-Brandenburg on the Havel River, and a detachment under his half brother Volmar to the north at Havelsberg.
Frederick William spotted the gap, and moved his army to Rathenow, blocking an intact bridge over the Havel. Wrangel ordered Volmar to circle to the east, crossing a bridge at Fehrbellin, but that bridge had been destroyed. While the Swedes were repairing the bridge, the Brandenburgers arrived from the west and took up a strong position on higher ground overlooking the Swedish position. Despite this strong position, the Brandenburgers were unable to inflict a heavy defeat on the Swedes. While the Swedish right wing held off the Brandenburg attack, the rest of the army was able to cross over an improvised bridge, followed by the right, which then covered the retreat. The Swedes lost 600 men in the battle, but the two parts of the army were able to reunite.
Frederick William turned the relativity minor victory at Fehrbellin into a major publicity triumph. It had disastrous results for Sweden, encouraging the Emperor Leopold, the Dutch and the Danes to join in the fighting. However, it was not as decisive as it is sometimes portrayed – the Swedish position in Pomerania did not immediately collapse, and their last foothold in Germany, at Greifswald, 100 miles due north of Berlin, did not fall until November 1678, only to be returned to Sweden in the peace of St. Germain (29 June 1679).