By 1546 it seems that walking any distance was difficult and painful for the King. He already sometimes used a ‘tram’ (a type of wheelchair) to get around the palaces, and had a ‘device’ to get him up and down stairs. And his gross obesity and immobility would have made him prone to yet another problem, deep-vein thrombosis in his legs, both of which were now described as ulcerated (a condition consistent with diabetes). Blood clots would form in the legs, then could become detached and travel to the lungs (to trigger a pulmonary embolism). If the clot can dissolve, a patient can survive, but otherwise dies. The descriptions of Henry’s medical crises from 1541 seem consistent with a series of pulmonary embolisms, the last of which killed him in January 1547, although he would also be liable to strokes or heart attacks – all his organs would have been under tremendous strain.

If Henry did become diabetic as well as morbidly obese around 1540, he could also have become impotent. He had no problems in making his first three wives pregnant, but none of his last three conceived. Catherine Parr was in some ways an odd choice for a sixth wife; she was past thirty and had already had two childless marriages (neither, as in popular myth, to men too old to sire a child). Henry badly needed a second male heir. Prince Edward (again contrary to popular myth) was not a sickly child, but child mortality in Tudor England was high and, if he died, Henry would be back where he had started, without a male heir. Yet in 1543 he married a woman who was a most unlikely candidate to bear a child. Catherine Parr did not fall pregnant during her three-and-a-half-year marriage to Henry, but she conceived during her subsequent marriage to Thomas Seymour. So Catherine was not incapable of bearing children; but Henry by now may well have been.