Yoko Ono's symbolic acorn trees remembered 20 years on

Acorns were planted on Coventry Cathedral grounds, as well as being sent to world leaders

It was 20 years ago today that Yoko Ono visited Coventry Cathedral to plant a new pair of oak tree saplings as a symbol of peace.

At the event on 14 October 2005, Ono revealed to hundreds of people who had gathered that the city was where her and John Lennon's campaign for peace had began in 1968.

"It was here in Coventry the first public manifestation of our message occurred, so it is great to be back here 37 years later, to continue something we started together, John would have loved it," she said at the time.

The pair had originally visited the site in the late 60s, travelling to the city to submit their Acorns for Peace sculpture in an exhibition at the cathedral.

The artwork consisted of a circular white wrought-iron seat that surrounded two acorns, which would grow over time inside as a living sculpture.

However, their visit in 1968 caused a row with cathedral authorities who ended up moving the installation - infuriating Lennon - while the acorns were dug up and stolen a few weeks later by Beatles fans.

Last year, Pete Chambers, of Coventry Music Museum, told the BBC that members of the cathedral made the mistake of questioning Yoko on whether the project was even art.

"By all accounts this resulted in a lot of shouting," he said.

"Later John got his trusty chauffeur to come back to Coventry and take the bench away."

The two oak trees planted by Yoko Ono in 2005 stand in Cuckoo Lane, close to the Cathedral ruins.

The planting in 1968 was one of the couple's first missions of peace, and an entry into the prestigious Exhibition of British Sculpture which was being held in the cathedral's ruins at the time.

John, Yoko and the acorns travelled to the city in his white Rolls Royce, famously equipped with a record player and telephone.

The nuts were buried beneath the circular white wrought iron seat on grass outside the Chapel of Unity.

It had all been meticulously planned, with the acorns planted in east and westerly positions, symbolising the meeting of the couple and the union of their two cultures, marking the start of the couple's campaign for peace, with a plaque that read: "Yoko by John, John by Yoko".

The pair went on to send acorns to leaders across the world as part of their anti-war message.

Yoko Ono returned to the city in 2005 to plant Japanese oak trees at the Cathedral

Now, the two oak trees, which were planted by Yoko Ono from saplings, stand in Cuckoo Lane close to the Cathedral ruins.

Last year, the acorns went on display at The Beatles Museum in Liverpool after a retired police officer found them in his possession.

Former Warwickshire Police traffic sergeant Mike Davies said he had discovered them in a box while tidying up ahead of his retirement.

The 88-year-old said they had been brought into Nuneaton police station by a man who had been caught drink-driving outside Bedworth.

He said the driver and his girlfriend were fans who had returned to the cathedral after the planting ceremony and stolen the acorns, coating them in clear nail varnish to preserve them.

A replica bench, made for the Theatre Absolute play The Lennon Bench. is now on display at Coventry Music Museum.

The acorns are now on display at the Beatles Museum in Liverpool