Where did billiards start?

Pocket billiards is generally agreed to have morphed from an outdoor game played on grass, with mallets very similar to croquet. It was moved indoors, and rails and pockets added as the game evolved. Perhaps the single most important revolution to the game was the addition of leather tips, which added a great deal of control to the "strike".

One key point is that I have described pocket billiards, which is...billiards with pockets. Billiards refers to any game where one has balls that strike each other.