The phrase “back to square one” originates in the game of snakes and ladders, or at least was influenced by it – the earliest attestation of the phrase refers to the game: “Withal he has the problem of maintaining the interest of the reader who is always being sent back to square one in a sort of intellectual game of snakes and ladders.

Snakes and Ladders is an ancient Indian board game.

source: http://en.wikipedia.org/wiki/Snakes_and_Ladders