elizabeth and mary queen of scots

Answer 1

They both had a claim to the English throne. Elizabeth because she was the daughter of King Henry VIII and Mary Stuart (Queen of Scotland) because she was the daughter of Henry's sister - making her Elizabeth's cousin.

To add to this, Elizabeth was a Protestant and Mary was a Catholic.

Neither trusted the other when it came to their respective rights to the crown, and their religious differences were always fuel for their respective religious supporters.