Previous king: Edward VI (brother) Reigned: 1553-1558 Next queen: Elizabeth I (sister)
Since Edward VI had no children, Mary I became queen when he died. There was an attempt by Edward's advisers to make Lady Jane Grey queen instead, but the country remained loyal to Mary.
Mary had remained a Roman Catholic when her father Henry VIII founded the Church of England. Once queen, she re-introduced Catholicism to England. In 1554, she married Philip II of Spain (see right). This was unpopular, as people thought that England would be under control of a foreign country. There was a rebellion, with an attempt to make Lady Jane Grey queen again, but it failed, and Lady Jane Grey was executed.
The wife of a king of England is called a queen, but Mary was the first sovereign queen of England, to rule in her own right.