 This ended, after English intervention, with the surrender of Edinburgh Castle in May 1573.In 1578 a Second Book of Discipline was adopted, which was much more clearly Presbyterian in outlook.In England, Mary became a focal point for Catholic conspirators and was eventually executed for treason in 1587 on the orders of her kinswoman Elizabeth I. James was Calvinist in doctrine, but strongly supported episcopacy and resisted the independence, or even right to interfere in government, of the Kirk, which became associated with the followers of Andrew Melville, known as the Melvillians.