Lubomirski was Krajczy of the Crown and Secretary of the King since 1620, voivode (military commander) of the Ruthenian Voivodeship since 1628 (or 1625?

After the death of Jan Karol Chodkiewicz, in the rank of regimentarz he commanded the Polish forces during the battle of Chocim in 1621 (see Moldavian Magnate Wars).

In 1634 Lubomirski was second in command in Ukraine, after Stanisław Koniecpolski, and in 1635 he befriended a French negotiator at the Treaty of Sztumska Wieś, Claude de Mesmes, Count Avaux.

[1] They had five children together: Aleksander Michał, Jerzy Sebastian, Konstanty Jacek, Konstancja and Anna Krystyna.

By 1642 he owned 10 castles, 12 towns, 300 villages and many forests, lakes, mills and even private salt mines, making him one of the wealthiest magnates in Poland of his time.