Executive authority in Bermuda is vested in the monarch and is exercised on her behalf by the Governor. The governor is appointed by the Queen on the advice of the British Government. The current governor is George Fergusson; he was sworn in on 23 May 2012. There is also a Deputy Governor (currently David Arkley JP). Defence and foreign affairs are carried out by the United Kingdom, which also retains responsibility to ensure good government. It must approve any changes to the Constitution of Bermuda. Bermuda is classified as a British Overseas Territory, but it is the oldest British colony. In 1620, a Royal Assent granted Bermuda limited self-governance; its Parliament is the fifth oldest in the world, behind the Parliament of the United Kingdom, the Tynwald of the Isle of Man, the Althing of Iceland, and Sejm of Poland. Of these, only Bermuda's and the Isle of Man's Tynwald have been in continuous existence since 1620.

The Governor of Bermuda gets his authority from whom?