In the autumn 1609, Strus joined the Siege of Smolensk (1609–11), leading a unit of 150 Hussars, 50 Cossacks and 100 infantry. On July 4, 1610, he fought in the Battle of Klushino, after which he rushed with Aleksander Zborowski and Mikolaj Scibor Marchocki to King Zygmunt III Waza, presenting to him captured flags of the enemy (July 17). In the spring of 1612, together with 1000 infantry and 3000 cavalry, Strus joined forces of Lithuanian Hetman Jan Karol Chodkiewicz, which was sent to reinforce Commonwealth garrison of the Moscow Kremlin.