‘Distinguished old gent,’ remarked the soldier at the gate of the Royal Hospital in Chelsea, watching Jasper Ridley walk down towards Tite Street, and it struck me for the first time not that he was distinguished-looking (he always had been) but that he was old. He must have been aging for a long time and I hadn’t noticed, partly because he had never looked young, either. His thick curly hair had whitened over the years but so gradually that it marked no special change, and with no loss of the thickness and curliness that, photographs showed, had made him such a pretty child His general look was constant, like everything else about him. He was the most consistent, unchanging, conscientious of men. Exactly 50 years ago he gave up the law and took to full-time writing, and for the next 50 years he carried on as he had begun, writing historical biographies.

There were occasional interlopers in his work, but they were few. A rather forbidding legal one called Law of Carriage of Goods by Land, Sea and Air appeared in the same year as his first biography, one of Nicholas Ridley, a distant kinsman. A Sussex Childhood and Sussex Women testified to his lifelong connection with his birthplace, and A History of England, The Roundheads, The Tudor Age, The Love Letters of Henry VIII and The Freemasons opened things up at long intervals into more general history. But for the rest, it was all biographies, life stories set in their historical context, puzzlingly far apart in time and space so that one wondered how a single writer could possibly keep track of such disparate lives and their backgrounds: a clutch of early Protestants, several Tudors (Mary, her father, her sister), a zoom ahead into the nineteenth century (Palmerston, for which he was awarded the James Tait Black Memorial Prize); across the Channel for Napoleon III and the Empress Eugénie, then to South America and Italy for Garibaldi, Mexico for Maximilian and Juarez and, most recently, into modern times with Tito and Mussolini.

Each new person he dealt with seemed to take Jasper over while he was writing. It became a joke among his friends that he was obsessed with this or that character he had on hand (‘Which is it now – the Empress Eugénie?’) While it lasted it seemed an almost passionate attachment, and these enthusiasms were somehow endearing. They suggested a rich imaginative life under the staid exterior. But of course the dispersal of his gifts and interests meant that he was never – or seldom – taken as seriously as he might have liked to be as a historian. No one, it was felt, could possibly be expert on so many historical periods, places, figures. He was a generalist, and presumably chose to be one, which meant his books were good public-library fodder rather than scholarly tomes. They nearly always had good reviews, addressed to serious but generalist readers who found his research sound, his writing readable and his arguments generally persuasive; the non-fiction equivalent of the upper-middlebrow novel – intelligent, accessible, not too demanding.

But, Jasper being Jasper, there was more to his life than that, or than them. I suggested at the start that he was almost weirdly conscientious. The only child of a remarkable woman who owned and organised a large village community, he seemed early to have learned the importance of duty towards others, of ritual in everyday life, of an almost stately sense of responsibility. Among his many activities and interests (chess, tennis, walking, opera), he found time – heaven knows how, considering his workload – to involve himself in others’ activities. As President of the Tunbridge Wells and District Writers’ Circle, he drove about to meetings of every size and sort; as Chairman, also, of the Ramblers Association in Tunbridge Wells, he got about in probably more enjoyable ways on foot. As a vice-president for life of English PEN he was invited to attend management meetings whenever he liked, something no other vice-president would have dreamt of doing, especially when it meant a train journey to London from Tunbridge Wells and then a cross-London trip to an awkward bit of Chelsea. But Jasper, for all the hassle, turned up regularly to watch and listen, presumably because it was expected of him – and, as so often seemed to happen in his life, got precious little thanks for it (no PEN representative at his funeral, as far as I could see). More noticeably appreciated were his stints as Master of the Carpenters, one of those London livery companies so mysterious to outsiders, so full of good works and ritual, where, on the evenings of their enormously grand dinners, he would preside in a gown with furry tippets, addressed by everyone as ‘Master’, while, from the gallery, exquisite singing floated down as a prelude to some of the most boring after-dinner speeches anyone can ever have heard. So I remember him, an earnest, kindly man, oddly unfulfilled (one felt – but who isn’t?), yet deserving, not just for his looks, the soldier’s description of him as ‘distinguished old gent.’