'I could feel rising in me a mood of immoderate frustration and anger such as I suffered so frequently in my Former Life, ' he says, 'and I knew that I had to force myself to contain it, or lose all possibility of obtaining the thing I wanted above all others'. And it is this universal struggle that makes him such a recognizable and likeable figure. The problem is that his struggle is not with his position, shaped as it is by regal whim and fluctuating fortune, but with his own character. The question posed by the book is whether Merivel can wise up and embrace life after burning the wick so long and so low. Although his attempts at an audience with the Sun King are dismissed, he gains the affections of Madame de Flamanville, the erotically charged wife of a gay Colonel in the Swiss Guards. What follows is his Jeremy Clarkson phase, in which he takes his mid-life paunch and rocks up at the famed hall of mirrors, bedecked in the latest Bourbon fashions and a look of gone-to-seed awkwardness.

He obtains an introduction to the court of Louis XIV at Versailles. When Margaret departs for a season in Cornwall, Merivel attempts to stave off depression by calling in a favour from the King. In Restoration he went from being a young medical student to an accidental vet to the kennels of King Charles II, from royal confidant to cuckolded husband, all the while roistering around the corridors of power like a jester on heat. Robert Merivel is one of those literary heroes, like Henry Fielding's Tom Jones, who wins one over by dint of his sheer good will, momentum and fecklessness. It's every bit the 17th-century romp that its predecessor was rambunctious, funny and tender, with perhaps the added quality of age-worn wisdom – both of its author and protagonist – to add to all the cavorting misadventure.

With Merivel: A Man of His Time she has created an unadulterated delight. Yet a quarter of century after the first book, Tremain has taken the challenge and met it. It risks both critical mauling and readers' wrath. Writing a sequel to a novel as loved as Rose Tremain's Restoration is a precarious endeavour.

Letters to mr henshaw