“On 17th July 1917 the Privy Council proclaimed that henceforth the royal family would be called the House of Windsor, having divested itself of its previous surname, as well as ‘all other German degrees, styles, titles, dignatories, honours and appelations’. After a number of alternatives were considered – including Plantagenet, York, England, Lancaster, d’Este and Fitzroy – King George V’s private secretary Lord Stamfordham’s suggestion of Windsor was adopted, after a minor title once held by Edward III.

This anti-German gesture, made at a critical juncture of the First World War, produced one of Kaiser William II’s few jokes, when he remarked with heavy Teutonic humour that he looked forward to attending a performance of The Merry Wives of Saxe-Coburg-Gotha. A more serious and altogether grander criticism came from the Bavarian Count Albrecht von Montgelas, who observed that ‘the true royal tradition died on that day in 1917 when, for a mere war, King George V changed his name.’

The effect in Britain was instantaneous and wholly positive. With the whole family swapping Germanic-sounding for overtly British names – the Teck family became the Cambridges and took the earldom of Athlone, the Battenbergs were transformed into the Mountbattens with the marquisate of Milford Haven – the royal family proclaimed itself thoroughly British, to national applause. Despite the whispering campaign against some members of his family that they were pro-German, George V had always been quintessentially British, finding German ‘a rotten language’. When H.G. Wells criticised ‘an alien and uninspiring court’, the King retorted, ‘I may be uninspiring, but I’ll be damned if I’m an alien!”