This is an extraordinary biography. It is a story of one of the leading figures in Royal circles, friend of Edward VIII and mentor to Prince Charles, whose life was cut short when he and some of his closest relatives were murdered by the IRA in 1979.

But it is no eulogy for a Royal figure whose Christian name lives on in the names of two of the Duke of Cambridge’s children. As Mountbatten himself once said ” No biography has any value unless it is written with warts and all.”

This biography written by historian Andrew Lownie is full of warts as well as some startling disclosures. It draws on previously unknown information – despite many previous biographies – and still does not present a complete picture because of decisions by the British government, the United States government and his own estate at Broadlands not to release all the documents relevant to his life.

What emerges is a complicated man who is full of hubris, self importance, a natural risk taker whose life was privileged, setting himself,apart from the rest of society with his retinue of household staff. He was also extraordinarily methodical.

It goes into detail of the love life of his wife, Edwina, a wealthy socialite, whose adventurous affairs took in Hollywood film stars and India’s first leader, Nehru when Lord Mountbatten was the last governor general of India. Until World War II she lived the life of a bored heiress making exotic trips to remote places before finding an amazing drive to help with the war effort organising and looking after the interests of the troops injured in action.

The book describes his loves which in their ” open marriage” and reveals that he was also bisexual after tracing one of his gay lovers. It also contains an extraordinary chapter entitled ” Rumours” which goes on to suggest that he may also have been a paedophile, It describes claims by a former boy , Richard Kerr who was in the notorious Kincora children’s home in Belfast , where it is proven that boys were subject to child sexual abuse, that MountBatten abused him.

Interestingly the Northern Ireland Office still hasn’t released all the documents about this home even though the events took place over 50 years ago.

The book is fascinating in its description of their wealthy life style – which might sound dated – but in fact due to the growing inequality in the UK could well be replicated today by some of the uber wealthy from Russian oligarchs, Hong Kong billionaires, tech billionaires rather than Royalty.

There are some extraordinary revelations particularly during his career in the Royal Navy. His hubris and risk taking, and a habit of not necessarily following orders, was responsible for a disaster early in World War II When he ignored orders to pick up 600 captured seamen and chase a German battleship with the result the seamen spent the war in internment camps.

The book to an extent exonerates him from the failed raid on Dieppe during the war but it shows that because of his connections to King George V and Churchill he would never be taken to task for his failures.

This hubris actually led to his assassination in 1979 when he ignored repeated advice from the security services and the Irish embassy not to go his country home in the Republic during August. They knew he was an IRA target.

The book contains a remarkable disclosure of how one young corporal, Graham Yuill, responsible for the Mountabatten’s security, spotted a car near his yacht Shadow 5 which was identified as a vehicle used by the IRA for gun running and carrying bombs. His report was ignored and not taken into account when the Garda took over security. The yacht was then blown up killing Mountbatten, his 83 year old mother, his daughter,Patricia and husband John; two 14 year old twins and a 15 year old friend.

The report has been subject to a 40 year old gagging order which was only lifted two years ago. This is just one remarkable disclosure in this fascinating book. Well worth a read.

The Mountbattens: Their Lives and Loves by Andrew Lownie. Bonnier Books. £20