The plaque was unveiled at 23 Heddon Street, just off Regent Street, London, W1, where the photograph on the front cover of the album was taken–a fact little known until now.

David Shaw, Head of the Regent Street Portfolio at The Crown Estate, said: "Regent Street is famous for many cultural firsts. Not only was the first British cinema opened in Regent Street but the seminal album that launched Ziggy Stardust's arrival on planet earth had its spiritual home in Heddon Street which is now the food quarter to Regent Street. Regent Street is proud of the association with David Bowie, a true British cultural icon."

Unveiling the plaque, Gary Kemp (Spandau Ballet) said: "Ziggy was the ultimate messianic rock star, and with him David Bowie successfully blurred the lines not just between boys and girls, but himself and his creation. Bowie was Ziggy come to save us–and I bought him hook, eyeliner and haircut. It seems right that it should be the job of a fan boy and I am very honoured."

Attending the VIP breakfast were Mick Woodmansey and Trevor Bolder, original members of the band Spiders From Mars; illustrator Terry Pastor, who created the iconic album cover; and record producer Ken Scott, who came from his home in Los Angeles.

Part of The Crown Estate's ongoing vision for the development of Regent Street and surrounding areas, Heddon Street today is completely different from that of 1972, when the album cover was created. Now one of Regent Street's main Food Quarters, it has been transformed into a pedestrianised courtyard ideal for al fresco dining with restaurants including Momo, Aubaine, Below Zero, The Ice Bar, Strada, Piccolino's, Strawberry Moons and The Living Room.

Back in 1972, the BOWIE album depicts 'Ziggy' outside on a cold wet January night with his foot resting on a step outside 23 Heddon Street. The late Brian Ward had rented a space upstairs in the building as a makeshift photographic studio, and had already shot 17 pictures when he persuaded BOWIE to step outside onto Heddon Street. The other band members thought it too cold and declined to join him for the picture. Wearing the green jumpsuit that he later wore on the BBC 2 TV show "The Old Grey Whistle Test," BOWIE posed for the photograph. The images were shot using Royal –X – Pan black and white film and then lovingly hand coloured by artist Terry Pastor. In the finished image, Ziggy's jumpsuit is coloured blue.

"It was cold and it rained and I felt like an actor," BOWIE recollected. "We did the photographs outside on a rainy night and then upstairs in the studio we did the Clockwork Orange look-a-likes that became the inner album sleeve."

The iconic image cover catapulted DAVID BOWIE to international stardom, creating an army of pop stars with spikey hair and edgy alter egos, a trend which later evolved into the glam rock movement for which Ziggy was the poster boy. This plaque pays homage to an enduring iconic creation of British Pop, meaning fans from all over the world can visit the place where the dynamic character of Ziggy was immortalised on camera.

The Full Speech by Gary Kemp: Thank you David and all who have worked to make this possible at the Crown Estate.

It's strange that I used to be chased out of the street with my felt-tip pen for scrawling 'Ziggy Woz Here' and now I'm unveiling a plaque. I guess the Ziggy Stardust generation has really come of age.

On 13th January 1972, Ziggy Stardust was first spotted here and snapped by photographer Brian Ward. He was caught standing against this wall where we are now, underneath a sign for a furrier's, holding what looked like a guitar but could easily have been a ray gun.

Ziggy appeared from the shadows of a much darker London than the one we know now, certainly no pedestrian walkways and alfresco dining; a much poorer, less glamorous London, still in the shadow of the Second World War. And that's the important context.

He was the ultimate messianic rock star, and with him David Bowie successfully blurred the lines not just between boys and girls, but himself and his creation. Bowie was Ziggy come to save us–and I bought him hook, eyeliner and haircut.

Looking back to what we can now call the Golden age of Rock, this was a cultural highpoint of some significance. The album The Rise and Fall of Ziggy Stardust and the Spiders from Mars not only changed Bowie's life forever, it also changed mine, allowing a generation of adolescents to find an escape from the ennui of existence and the hard times of the early seventies.

As a teenager any visit to the West End would have to involve a pilgrimage to here. We'd stare at the phone box that Ziggy had obviously teleported himself into, and then try to fathom the meaning behind the K. West sign. K West? Yes, Quest! It all made sense back then.

I believe that Ziggy is now one of London's great fictional characters and stands alongside the likes of Dorian Gray and the Artful Dodger, as well as antiheroes such as Steerpike and of course Clockwork Orange's Alex.

But it seems right that it should be the job of a fanboy, to have this honour; after all, Ziggy is no longer actually with us, killed off by his creator in 1973. And as for that creator, well he is currently nurturing his well-earned enigma in New York. In any case, as Ziggy once sang: 'He'd like to come and meet us, but he thinks he'll blow our minds.'

Before I unveil this I'd like to say how thrilled we are to have two of the Spiders here, Woody Woodmansey and Trevor Bolder, and also Terry Pastor whose hand tinting of the photograph added to its theatricality, giving it the look of a film-noir setting. And also choosing Ziggy's blond hair, which added to his otherworldliness.

Can we also think of absent heroes–Ziggy's faithful lieutenant and my favourite guitarist of all time, who rode shotgun throughout the album–Mick Ronson. And a special mention to the beautiful Freddie Burretti who created the clothes that Ziggy wore.