The Line of Succession to the British throne is governed by laws centuries old. It was the Act of Union in 1800 (restating the 1701 Act of Settlement William and Mary’s Bill of Rights in 1689) that meant only Protestant heirs of Princess Sophia, Electress of Hanover and granddaughter of James I, were eligible to succeed. Royal History
The Queen will currently be succeeded by..
1. Prince Charles, Prince of Wales (Duke of Cornwall, Duke of Rothesay, Earl of Carrick, Earl of Chester, Baron of Renfrew, Prince and Great Steward of Scotland and Lord of the Isles) – heir apparent (= Camilla, Duchess of Cornwall m.2005)
2. Prince William, Duke of Cambridge, Earl of Strathearn and Baron Carrickfergus (= Catherine, Duchess of Cambridge m. 2011)
3. Prince George of Cambridge
4. Princess Charlotte of Cambridge
5. Prince Henry of Wales
6. Prince Andrew, Duke of York, Earl of Inverness and Baron Killyleagh
7. Princess Beatrice of York
8. Princess Eugenie of York
9. Prince Edward, Earl of Wessex and Viscount Severn (= Sophie, Countess of Wessex m. 1999)
10. James, Viscount Severn
11. The Lady Louise Mountbatten-Windsor
12. Princess Anne, Princess Royal (= Sir Tim Lawrence, m. 1973)
13. Peter Phillips (= Autumn Phillips, m. 2004)
14. Savannah Phillips
15. Isla Phillips
16. Zara Tindall (= Mike Tindall, m. 2011)
17. Mia Tindall
18. David Armstrong-Jones, Earl of Snowdon (= Serena, Countess of Snowdon m. 1993)
19. Charles Armstrong-Jones, Viscount Linley
20. Lady Margarita Armstrong-Jones
The Sovereign must be in communion with, i.e. a member of, the Church of England. To sit on the throne, one must swear to preserve the Church of England and the Church of Scotland and uphold a Protestant succession.
The 2013 Succession to the Crown Act made amendments to the aforementioned Bill of Rights and Act of Settlement: it replaced primogeniture with absolute primogeniture (the eldest child takes precedent, regardless of sex) and stated that any Royal who marries a Roman Catholic, so long as they remain Protestant themselves, may remain in the line of succession. Before this, those who married a Catholic were disqualified; this Act applies to anyone born from the 28th of October 2011 onwards, and was effected in March 2015.
Following the laws of Great Britain, The Prince of Wales will take the throne, and this is only right. Her Majesty will not abdicate since she took the vow she made to her people at her coronation very seriously, and passing over a legitimate heir would cause countless problems for the UK. Read why Prince Charles must be our next King here.