Site unseen: THE GARRISON CHURCH, PORTSMOUTH

This is where Charles II, "the Merrie Monarch", finally got married. One of England's randiest kings actually had a headache on his wedding night and failed to rise to the occasion. How do we know? Did a housemaid listen outside the door? No. It was the King himself who let the cat out of the bag. Writing to Lord Clarendon, his adviser in May 1662, Charles II was explicit: "It was happy for the honour of the nation I was not put to the consummation of the marriage last night, for I was so sleepy, by having slept but two hours in my journey, that I was afraid that matters would have gone very sleepily."

Where did all this not take place? Not London or Windsor but in the naval town of Portsmouth, where Charles II married Catherine of Braganza - in the Garrison Church.

After his restoration to the throne two years earlier, Charles had cut a swathe through the court beauties, amassing several illegitimate children who were later fobbed off with titles and chunks of land.

His choice of wife, however, was a diplomatic affair and Catherine of Braganza was judged to be the best bet to help ward off danger from Holland and Spain. Neither bride nor groom had met. Catherine was shipped over from Portugal with a retinue of virginal ladies.

St Thomas's, the parish church of Portsmouth (and now the cathedral), was in a terrible state after being bombarded by Cromwell's parliamentary forces during the Civil War. Fortunately, there was another church close at hand, Domus Dei, which had once been a hospice for travellers and the sick.

Here it was, on Wednesday 21 May 1662, that the Merrie Monarch was married. Had the old lecher finally met his match? Unfortunately, no. She loved him, he loved many others. They had no children and the Stuart regime soon came to an ignominious end. As for the church, it was bombed in the Second World War and is now being restored.

But might the history of England have been different if Charles had not had that headache?

The Garrison Church is in Penny Street, Portsmouth.