The shop, founded by Mr Fleming's grandfather in 1908, has traded non-stop in Castle Road ever since, and was once a favourite of King George V's wife, Mary, who would peruse the store in search of collectables during the 1920s.

It has moved just once, when the German Luftwaffe 'redecorated' their old premises in a massive city-wide air raid in 1941 – a scene witnessed by Alfred Fleming, son of the store's founder, who watched the city burn as he returned from an RAF sortie.

The direct hit forced them to relocate to the iconic Tudor-style clock tower, which the business has occupied ever since.

It stands as the last outpost of what was once a mini-empire, which had included a string of shops reaching from Portsmouth to Pall Mall in London, and a flourishing worldwide export business.

The firm continues to trade from Wednesdays to Fridays, 9.30am to 5pm, in the basement of the clock tower, and is now planning a special birthday exhibition, featuring a range of the store's Portsmouth artefacts to celebrate its full century in business.

Although trade is not what it once was, Mr Fleming is confident that his own slice of Portsmouth's history will still be doing deals for years to come in the 21st century.

He said: 'Castle Road has stayed, to a large degree, exactly as it was. If you take a look at old images of the street, it does look almost exactly the same.

'Will we be here in 50 years? Me, personally, no! But there'll always be a market for fine furniture and antiques, although we find younger people are more minimalist in their approach to what they buy.

'What we're finding now is that the prices of many antique pieces of furniture are cheaper than a lot of modern-made examples.'

The Fleming Collection exhibition will be held at The Gallery, Number 10 High Street, Old Portsmouth, from Monday, September 22 to Friday, October 3, from 2pm to 4.30pm each day, and a parallel exhibition will be staged in the Castle Road shop.