Brusilov was born in Tiflis (now Tbilisi, Georgia). His father Aleksi Nikolaevich Brusilov was Russian and his mother, Anna Luiza Niestojemska, was Polish. Three generations of Brusilovs had served as officers in the tsar's army, his grandfather fighting in the defense against Napoleon's invasion of 1812. His father rose to the rank of Lieutenant General before dying of tuberculosis in 1856. Brusilov's mother died shortly afterwards, and the young orphan was raised by relatives in Kutaisi.