New heads for the Royal Navy and the RAF were among senior military appointments unveiled by Defence Secretary Philip Hammond today.
Admiral Sir George Zambellas will take over as First Sea Lord from April and Air Marshal Sir Andrew Pulford as Chief of the Air Staff from July - promoted to Air Chief Marshal.
General Sir Nicholas Houghton is replaced as Vice Chief of the Defence Staff by Air Chief Marshal Sir Stuart Peach.
His role as Commander Joint Forces Command will be filled in turn by Lieutenant General Richard Barrons, who will be promoted to the rank of general.
The identity of the new overall head of the armed forces will be announced in March - with General Houghton thought by observers to be the leading contender.
A new head of the Army will be announced "later in the year", the MoD said.
Admiral Zambellas, who began his 33-year Navy career flying helicopters and captained HMS Chatham during the Sierra Leone intervention in 2000, played a leading role in the 1997/98 Strategic Defence Review.
For most of last year he served as the Navy's Fleet Commander as well as commanding Nato maritime operations from it's UK headquarters in Northwood.
He will replace Admiral Sir Mark Stanhope.
Air Marshal Pulford is also a helicopter pilot by training, with 5,000 hours in Wessex and Chinook aircraft and operational service in Northern Ireland, the Falklands, Lebanon, the Balkans and the Gulf.
He will replace Air Chief Marshal Sir Stephen Dalton.