The Princess Royal has been awarded Army and RAF promotions in recognition of her “invaluable contribution and commitment to the military”, the Ministry of Defence (MoD) has said.

Anne, who celebrates her 70th birthday on Saturday, is now a General in the British Army and an Air Chief Marshal in the Royal Air Force.

Senior members of the royal family receive promotions to mark milestone birthdays and the Queen has approved the move.

Before the appointments Anne’s rank within the Army and RAF was linked to her existing roles as Colonel-in-Chief and Colonel of a number of regiments and Honorary Air Commodore of RAF Brize Norton.

The promotions bring her rank in the two services into line with her existing rank of Admiral in the Royal Navy.

Three official photographs of Anne have also been released to celebrate her seven decades – taken by celebrated photographer John Swannell.

The MoD said: “Her Royal Highness has been hugely supportive of the Armed Forces and undertaken a vast amount of work for the services over many years.

“This promotion on her 70th birthday recognises her invaluable contribution and commitment to the military.

“This includes long-term links with the Royal Navy, initially through the Women’s Royal Naval Service and her promotion to Admiral Chief Commandant in 2012.

“More recently, she visited the Royal Logistic Corps in Northern Ireland and paid tribute to the Royal Corps of Signals to mark their 100th birthday in June.”