Later that year, in August, he captured Velizh in September he participated in the siege of Velikiye Luki, and then took Zavoloc. On 11 August 1581 he received the nomination for the post of Grand Crown Hetman; this nomination, although uncontroversial at that time, was technically illegal. Following that he participated in the long and inconclusive Siege of Pskov, which ended with the Peace of Yam-Zapolsky in 1582. Though Zamoyski failed to capture Pskov, he drained the Russian resources, and the ongoing siege was a major reason for the final treaty, which was highly favorable to Poland.