What is the origin of the phrase "changing of the guards"?

I am not sure if it is the origin of the phrase but British Royal Palaces have had guards since the Restoration of the Monarchy in 1660 (Charles ll).

When the Monarch changed Palaces they changed the Guard.

The tradition continues and can be seen at Buckingham Palace in the forecourt.

The ceromony is known as 'The Changing of the Guards'

I would imagine that it would come from further back but that is the only factual one I know.

It could be the changing of the guard on the tomb of Christ but I have never heard it described from that.

The men you will see in front of Buckingham Palace (and other locations) are not just ceremonial guards but also serving Soldiers. While upholding the traditions of the past, they also perform duties throughout the world as professional soldiers and are known as some of the most elite and skilled soldiers in the British Army.

This is why Changes may occur in the guard change as the soldiers are required for operational duties.

The Household Division is made up of seven Regiments.
These comprise: The Household Cavalry Regiment - The Life Guards and The Blues and Royals; and five Regiments of Foot Guards.

The responsibility of guarding the Sovereign by the Household Troops (as they were known at the time) dates back to the time of Henry VII (1485-1509).

These are some of the best soldiers in the British Army and have fought in virtually every major area of conflict with great distinction since the 17th Century.

They also take an active role in protecting their Sovereign; at night they patrol the grounds of both Buckingham Palace and St. James's Palace.

It refers to the formal "guard mount" ceremony at the change of sentry shifts. +5

There are five Guards Regiments who are known as the Queens Guards. They are as follows in order of seniority. The Grenadier Guards, The Coldstream Guards, The Scots Guards, The Irish Guards, The Welsh Guards. Their main duties whilst in London are guarding Buckingham Palace and St James Palace. When the Queen is in residence at Buckingham Palace there a four Guardsmen on duty. When she is away there are only two. As you can well imagine it can be tiresome to stand to attention for long periods, so the guardsman is allowed to every now and again march in front of the palace and the back to his sentry box.After their tour of duty the guardsmen get relieved by four other guardsmen who have been resting and this is what’s called the changing of the guard. The guardsmen who are relieved can then rest themselves or eat their meals.

Some years ago the guards stood outside Buckingham Palace and were subject to the attentions of tourists who either tried to get them to talk which is forbidden or cut off their tunic buttons as souvenirs.It was for this reason they moved them behind the fence out of harms way.

Its not only the Guards regiments that do duties at the Palace, because at the moment the Royal Logistic Corp are doing royal duties. Unfortunately a drill instructor has had to do a crash drill course to show them how to march and do rifle drill.

The Guards are all part of the Household Brigade and The Life Guards & Blues Royals which are cavalry. Amongst other duties they can be seen outside the entrance to Horse Guards Parade in Whitehall London. These mounted soldiers also get unwanted attention from tourists who drop half eaten ice creams into their boots. On other occasions its coins and on others it women tourists posting their hotel address or telephone numbers.