Complex sentence: In 1634, he reached the position of lieutenant in the army of Catalonia and fought against the French tried to invade Leocata in Catalunya until the withdrawal of the besieging army.
Split into simpler sentences: In 1634, he obtained the charge of lieutenant in the army of Catalonia. In this army, he fought against the French, who were tried to invade Leocata (a place localized in Catalunya) until the withdrawal of the besieging army.