Poor Minna. A woman of limited artistic imagination, she never understood her husband. When she couldn’t follow where his intellect led, was it any surprise he turned to more creatively sympathetic muses? That at least is the picture painted by her self-centred husband in his partially revisionist autobiography Mein Leben. Those who followed – many of them fawning acolytes – toed the same line. For decades, that was the received wisdom regarding Minna Planer, first wife to Richard Wagner.

The reality was quite different, as Professor Dr Eva Rieger’s thorough and – thanks to Chris Walton’s excellent English translation – highly readable biography suggests. Of course, Mein Leben was written with Cosima, Wagner’s second wife, uppermost in his mind and published conveniently four years after Minna had died. As such, the composer, by then lauded as a giant of his profession, was keen to suggest that his first wife had meant less to him than his current domestic partner.

Wagner’s letters to Minna, many of them still extant despite his attempts to buy them back from Minna’s sister Natalie and destroy them, tell a different tale. Here we find the gushing 21-year-old musician who,...