An "extremely rare" piece of 17th century Dublin silver – "made in Dublin at the time of Oliver Cromwell" – that turned up at auction in England has returned to Ireland.

The silver porridge bowl, of a type known as a 'porringer', was described as "one of the rarest pieces of Irish silver ever to come to market" by Sworders auctioneers of Stansted Mountfitchet in Essex in November. It sold for £31,600 (about €37,000), over five times the top estimate of £6,000, to an anonymous bidder.

It has since emerged that the buyer was a private Irish collector. Dublin auctioneer Ian Whyte told The Irish Times that he had successfully bid on behalf of an unnamed client. He said there had been "at least five phone bidders and a couple of people in the saleroom up to 10k", and subsequently just himself and another telephone bidder.

Mystery initials

The bowl, which would have been used to eat porridge, soup or stew, was made in Dublin sometime between 1659 and 1663. It measures 2¾ inches high and 6¼ inches long from handle to handle and is known as ‘the IS porringer’ on account of its engraved initials. The identity of ‘IS’ remains unknown. The whereabouts of the ‘IS porringer’ was unknown for almost 50 years until earlier this year when Sworders valued items of silver from the family of an English private collector – Col SL Bibby CBE.

It is believed that Col Bibby had bought the porringer from an antiques dealer in London in 1967 for £3,000. Mr Whyte said “considering it sold in 1967 for £3,000 – the price of a three-bed semi in south Co Dublin at the time – the price paid today seems reasonable”.

Mr Whyte said his client, although “not a silver specialist”, was a “general collector of interesting and rare Irish items” and “liked the look of it, its rarity and the fact that it came from the Cromwellian period”.

He was delighted that the bowl, “a wonderful object of great historical importance, was coming back to Ireland as surviving items from the Cromwellian era are very rare”.

In the 1650s, Britain and Ireland were ruled by Oliver Cromwell, and subsequently his son Richard Cromwell during a few years of republican rule following the overthrow of the monarchy. The monarchy was restored in 1660.

Sworders said its research, in consultation with silver experts in Ireland, had identified that the porringer had been made in Dublin at the time but could not establish the name of the silversmith.