The monument, which records the deaths of four members of a Territorial Army unit of the Royal Field Artillery (RFA), is thought to have disappeared when the drill hall which housed it was flattened to make way for Queensgate.

But after patient detective work by the city branch of the Royal Artillery Association (RAA), the wooden memorial was tracked down to the museum, where it was lying unseen in the cellar.

Newly polished and restored, it now occupies a place of honour in the town hall, where it was unveiled by city mayor Cllr Marion Todd in front of members of the association and the Royal British Legion.

Association member Major John Moseley said there was satisfaction the memorial had been brought to light again and put on display with due reverence.

He said: "We are all very happy with it and are patting ourselves on the back.

"Some people might think no one would care about it because it only refers to four soldiers, but I think this tablet will be interesting to a lot of gunners and they will come and look at it."

The 1st Northamptonshire Battery of the RFA – so called because Peterborough was in Northants at the time – was formed on April 1, 1908 as part of the new Territorial Army.

As 'B' Battery of 270 Regiment RFA, it was drafted into frontline action in the First World War as part of the Middle East Expeditionary Force and helped fight the Turks and Germans in Palestine.

During that conflict, the four men recorded on the memorial lost their lives.

The wooden monument was displayed at the battery's drill hall, in Queen Street, which had been built for an earlier volunteer unit in 1867.

When the hall disappeared beneath what is now Marks and Spencer, the memorial seemed to have drifted into obscurity.

But Major Moseley said after RAA members saw an image of the memorial in a book about the battery's history, they decided to try to find it.

After some research it was tracked down to the museum, whose records suggested it had been kept there since at least 2001.

Major Moseley said: "It was damaged, but we wanted to get it repaired and said we would get to work and raise the £300 to do it."

Efforts to get the memorial put up in the cathedral failed, Major Moseley added.

But at a civic reception last month to mark the 100th anniversary of the creation of the battery, a new resting place was chosen.

Major Moseley said: "The mayor said, 'Let's have it in the town hall'. We said we would love to have it there, and it's worked out extremely well."