The battle of Erastfer was an early Russian victory over a Swedish army during the Great Northern War. During 1701 the main Swedish army, under Charles XII, had left Sweden’s Baltic provinces to campaign in Poland-Lithuania. An army 25,000 strong under Anton Wolmar von Schlippenbach was left in Estonia and Livonia to defend the area against any Russian attack, but much of that army had to be dispersed around the area. At Erastfer Schlippenbach was caught with only 3,800 men.
His opponent was Boris Sheremetev, dispatched into the Baltic by Peter the Great. At the end of December 1701 (OS) he led an army 13,000 strong (8,000 infantry, 5000 cavalry and 15-20 guns) on a march that caught Schlippenbach by surprise at Erastfer.
The Swedish army attacked and defeated the Russian advance guard. Schlippenbach then decided to withdraw to his fortified camp. During this manoeuvre the main Russian army attacked. The Swedish cavalry was driven away leaving the infantry isolated. Casualties were high amongst the Swedish infantry. Schlippenbach himself escaped from the battlefield, but would suffer a second, more serious defeat at Hummelshof (18/29 July 1702). These battles saw Swedish control of their Baltic provinces slowly destroyed and also served to increase the confidence of Peter the Great’s reformed Russian army, essential after the crushing defeat at Narva in 1700.