How does the British monarchy determine who is going to be the next queen or king to succeed the present king or queen?
Interestingly, the line of succession is determined and regulated by Parliament, a precedent set in the 1600's when James II left the country; Parliament decreed that he had abdicated the throne, but did not name James's young son as successor, instead offering the "postion" to James's daughter Mary and her husband, William of Orange. This precedent was formally recognized in the 1689 Bill of Rights (passed a year after James quit his job) and then again in the Act of Settlement of 1701. The line of succession as set up by Parliament also decrees that only Church of England members who are descendants of Electress Sophia of Hanover (1630-1714) are eligible to rule; Roman Catholics are specifically forbidden from rule, and a Sovereign of Britain may not marry a Roman Catholic. The first four people in line to the throne after Queen Elizabeth are her eldest son, the Prince of Wales (Prince Charles), followed by the her oldest grandson, the Duke of Cambridge (Prince William), Prince Henry of Wales (better known as Prince Harry), the Duke of York (Prince Andrew, younger brother of Prince Charles).