Stefan Batory replied with a series of three offensives against Russia, trying to cut off Livonia from the main Russian territories. During his first offensive in 1579 with 22,000 men, he retook Polatsk, Polish–Lithuanian troops also devastated Smolensk region, and Severia up to Starodoub. During the second, in 1580, with 29,000-strong army Stefan Batory took Velizh, Usvyat, Velikiye Luki. In 1581 the Lithuanians burnt down Staraya Russa, with a 100,000-strong army Stefan Batory started the Siege of Pskov but failed to take the fortress. The prolonged and inconclusive siege led to negotiations, which with the aid of papal legate Antonio Possevino ended in the peace of Jam Zapolski in which the Tsar renounced his claims to Livonia and Polotsk but conceded no core Russian territories. The peace lasted for a quarter of a century, until the Commonwealth forces invaded Russia in 1605.