When things antedate something else, they come before it, or happen earlier than it does. World War I antedates World War II.
Another way to say antedate is precede or predate. It's common to find the word antedate when people talk about history, for obvious reasons. Papyrus antedates modern paper, and paper antedates the desktop computer, which antedates the smartphone and tablet. Your parents' birth antedates your own, and your great-grandparents' lives antedate both yours and your parents'. In Latin, the prefix ante means "before."