In his interesting book Shakespeare: The World as Stage, Bill Bryson writes: “The marriage license itself is lost, but a separate document, the marriage bond, survives. On it Anne Hathaway is correctly identified. Shakespeare’s name is rendered as “Shagspere”—the first of many arrestingly variable renderings.”
Bryson speculates that Anne became pregnant prior to their marriage and there was a major scandal. The Shakespeare and Hathaway families were furious and a hasty marriage had to be arranged. Till 1604 the age of consent in Britain was twelve for a girl, fourteen for a boy.
Shakespeare: The World as Stage.