Aristobulus II was a ruler of the Hasmonean dynasty in ancient Judea, reigning from 66 to 63 BCE. He was the son of Alexander Jannaeus and Salome Alexandra, and he became king after the death of his mother. His reign was marked by internal conflict and a power struggle with his brother, Hyrcanus II, which led to a civil war. During his rule, Aristobulus II sought to expand his territory and strengthen his position. However, his reign ended when the Roman general Pompey intervened in the conflict, leading to Aristobulus's capture and the eventual annexation of Judea by Rome.