Already in his youth, as Lew Sapieha’s courtier, was involved in the affairs of the state. In 1600, as member of Lew Sapieha's retinue, he played a significant role in the negotiations with Moscovia, editing the planned alliance acts between Poland-Lithuania with the Muscovite state. In 1602, even as District-Governor of Wieliż, attended the drawing of the border between Poland-Lithuania and Moscovia – he became famous repelling a Russian troops attack on his own district. Then, during the wars of Sigismund III Vasa against his uncle Charles, the usurper King of Sweden, he served in the Lithuanian army. In 1605, he fought in the Battle of Kircholm. In 1606, as a member of the retinue of Mikołaj Oleśnicki, he escorted Maryna Mniszchówna to Moscow, where he led negotiations for an alliance with Tsar Dmitri.