Prince Harry is to join the Blues and Royals regiment of the Household Cavalry when he leaves Sandhurst, Clarence House has said.
New pictures of Harry on exercise coincide with the announcement
Harry, 21, is due to complete his Army officer training in April.
The news comes just weeks after Prince William also entered the Surrey academy to undertake the 44-week course.
The Household Cavalry recently had squadrons on operational duty with the UN and Nato in Bosnia and Kosovo, and is expected to return to Iraq.
The Ministry of Defence confirmed Harry could be sent there.
A spokesman for the MoD said: "It's fair to say that if his squadron goes to Iraq, he will probably go with it."
On being commissioned as an officer at Sandhurst, the prince will become a second lieutenant in the Household Cavalry.
He will then undertake specialist training to become a troop leader in the Royal Armoured Corps.
This post would mean leading a team of around 12 soldiers carrying out reconnaissance work.
Clarence House said the prince was impressed by the regiment's actions in conflict zones.
"He based his decision on the variety of roles which the regiment undertakes, including reconnaissance support to airborne forces right through to ceremonial duties," a spokesman said.
The prince entered Sandhurst in May 2005
"The prince was also attracted by the regiment's outstanding operational record in recent decades, most notably during the Falklands Conflict and the Gulf War, in Bosnia and Kosovo, in Iraq and in Northern Ireland."
The Household Cavalry is made up of both the Blues and Royals and the Life Guards - two of the oldest and most senior regiments in the British Army.
It is divided into the armoured division, with which Harry will train, and the mounted regiment, which is tasked with protecting the Queen.
Harry will escape sentry duties because he is an officer, and so will not be required to stand guard outside Buckingham Palace.
Since 1991, the Blues and Royals have had two reconnaissance squadrons based in Windsor, Berks, and a mounted ceremonial squadron in London.
Andrew Parker Bowles, the former husband of the Duchess of Cornwall, Harry's stepmother, served with the Blues and Royals.
James Hewitt also served in the Household Cavalry, but not in the Blues and Royals.