Prince Harry
Prince Harry at the Field of Remembrance (Reuters)

Prince Philip and Prince Harry have officially opened the Field of Remembrance at Westminster Abbey in London to pay tribute to the service men and women who have served in the armed forces since World War I.

Harry and Philip opened the memorial ahead of this year's Remembrance Day. It will be open to the public until 17 November.

Prince Harry
Harry joined Prince Philip in opening the memorial (Reuters)

Both laid a Cross of Remembrance in front of two wooden crosses marking the graves of unknown British soldiers from WWI and WWII. The Last Post was then played before a two minutes' silence was held.

Philip and Harry visited the plots in the Field of Remembrance and met with veterans from past and present conflicts.

Remembrance Day
Both Harry and Philip laid Remembrance Crosses at the graves of unknown soldiers (Reuters)

This is the 85th year the Field of Remembrance has been held at Westminster Abbey's grounds. The public will be able to visit the memorial daily from 9am until 4pm.

Both princes have a military background. Philip joined the British Royal Navy in 1939 when he was 18. He graduated from the Royal Naval College, Dartmouth, the following year.

Remembrance Day
The memorial pays tribute to service men and women who have fought since WWI (Reuters)

He served during WWII against two of his brothers-in-law, Prince Christopher of Hesse and Berthold, Margrave of Baden. In 1942 he became first lieutenant of the HMS Wallace and saved the ship from a night bomber attack during the invasion of Sicily the following year.

Harry entered the Royal Military Academy Sandhurst in 2005 and completed a 44-week training course as an Officer Cadet.

Remembrance Day
Philip and Harry both served in the military (Westminster Abbey/Twitter)

In 2008, he completed two months service with the British Army in Helmand province in Afghanistan.

He trained as a fully operational Army Air Corps helicopter pilot the following year and returned to Afghanistan as an Apache helicopter gunner in 2012 for a four month combat tour - during which time the Taliban threatened his life.

Also supporting Remembrance Day, Prince William and Kate Middleton will be hosting an event at Kensington Palace, where they will meet volunteers and military supporters.

Westminster Abbey
The Field of Remembrance will be open until 17 November (Reuters)