The cannon was first installed at Greenwich in 1807. © Greenwich Foundation

A 5.2 tonne Turkish cannon has been unveiled at the Old Royal Naval College, returning to Greenwich 200 years after it was first installed.

The cannon was originally captured by Admiral Sir John Duckworth from the island of Kinaliada in the Sea of Marmara near Istanbul in 1807.

It was then taken to London and presented to the Royal Naval Asylum, later the Greenwich Hospital School, in the same year, but when the school moved to Suffolk in 1933 the bronze cannon went with it.

Duncan Wilson (l) and Vice Admiral Peter Dunt (r) unveiling the cannon. © Greenwich Foundation

Its return to Greenwich and inauguration on October 20 2007 marked the beginning of the redevelopment of the current visitor centre at the Old Royal Naval College. The new interpretation and education centre, Discover Greenwich, will open in autumn 2009.

The barrel of the cannon was cast in 1790-91 in the reign of the Ottoman Sultan Selim III, while its cast-iron display carriage was made later by the Royal Carriage Department of the Royal Arsenal, Woolwich.

Its decorative plaques mark British naval victories including the Battle of the Nile and Trafalgar. It is thought that it was first presented to the Royal Naval Asylum to commemorate the battles that had created the need for such a school for children whose fathers had fallen in battle for the Royal Navy.