c. 1200, cunquearen, "to achieve" (a task), from Old French conquerre "conquer, defeat, vanquish," from Vulgar Latin *conquaerere (for Latin conquirere) "to search for, procure by effort, win," from assimilated form of Latin com-, here perhaps an intensive prefix (see com-), + quaerere "to seek, gain" (see query (v.)).
From c. 1300 as "to win (from); defeat (an adversary), overcome, subdue; make a conquest, be victorious, win or secure (something)." From early 14c. as "to acquire (a country) by force of arms." Related: Conquered; conquering.