Elizabeth had Mary held under guard throughout her time in England.
Mary’s presence in England caused problems for Elizabeth. Mary, with Catholic help, might try to seize the English throne but Elizabeth feared that if Mary returned to Scotland she would make the country a base for French and Catholic activities against England.
While Mary, Queen of Scots was Elizabeth I’s heir, many Catholics believed that Mary should be Queen.
Elizabeth was suspicious of Mary throughout her reign. Mary knew that she would have to please Elizabeth if she was to succeed her.
The two Queens did not get along well for the following reasons: