Paradise Now: The Extraordinary Life of Karl Lagerfeld by William Middleton review – the fashion planet's caped crusader

Costume historians will no doubt remember the day Karl Lagerfeld died in February 2019, leaving in his will lavish instructions for the continued care of his Burmese cat Choupette, as the precise moment where the pleasure finally came out of haute couture. Yes, it is possible that another eccentric in his own right will one day preside over a great house. But that doesn't seem, in the age of global conglomeration, terribly likely. "Creation", as Lagerfeld once said, "is not a democratic process". The more people (I mean accountants) who put their oars in it, the more likely you are to have half a dozen good camel coats on a catwalk than the kind of show, refined but wildly exuberant, which could make the late André Leon Talley of American Vogue cry with joy. Lagerfeld wearing a cape, fan, monocle and ponytail was the last of the last and he deserves a serious biography.

Does Paradise Now: Life Extraordinary of Karl Lagerfeld do the job? Or is it, like a web, only halfway? William Middleton, its author, certainly has a sense of fashion: he ran the Paris office of Women's Wear Daily. But the problem with insiders is that their respect is usually too ardent, and their need to stay on good terms with the big names in their world too powerful, for the required distance from biography. Yes, it gives us Kaiser Karl's long reign in full, from his peculiar childhood in Germany to the lonely months at the end when he was secretly battling cancer, leaving out – at least the feeling – not a single parts he threw along the way.

Among his interviewees are the muses of designer Inès de la Fressange, with whom Lagerfeld fell out, and Amanda Harlech, whom he pinched under the nose of Jean Galliano. It even gets to the heart of Lagerfeld's bizarre relationship with the love of his life, Jacques de Bascher, a French dandy who died of an AIDS-related illness in 1989 (and cheated on him with Yves Saint Laurent). Somehow, though, it does a pretty boring job. The book wants something that its subject, who liked to drink Coca-Cola in Lalique cups, knew perfectly well: vulgarity. In this case, the vulgarity involved in finding enemies as well as friends, and taking a funny look at the ridiculous, the stupid and the often obscene.

Lagerfeld was born in 1933 to polyglot parents who forced him to read Goethe as a child. His father had earned his money in condensed milk; his mother was a former Nazi party member - there is a photo of a four-year-old Karl standing in front of a flag pole at the family estate near Hamburg, atop which flies a swastika - who often treated his son with contempt . "Your nose is like a potato!" she liked to tell him.

Lagerfeld, however, was not one to cry in a corner. At four o'clock he asked if he could have a valet for his birthday. At the age of 19 he had left for Paris, where shortly after his arrival he had won the Woolmark prize for his design of a "cocktail coat" (it had three-quarter sleeves, pockets clad and - here is the little revolution - a plunging neckline in the back). Thanks to this, he was quickly apprenticed to Balmain, and from there everything else followed. In 1958, he joined Jean Patou. In 1962, he began to draw for the young Chloé. Three years later, he also works for Fendi. Finally, in 1983, he took over the management of Chanel. Prior to his arrival, Chanel had only one boutique and perfume accounted for around 90% of its business. During his 36-year reign, he took it from near bankruptcy to $11bn (£9bn) in sales.