Charles Spencer, the brother ofBritain’s late Princess Diana, is to publish a book about his sister’s life,promising to divulge the ​truth about her ahead of the 30th anniversary of her ‌death.

Diana, the first wife of KingCharles, was killed aged 36 in August 1997 when the car carrying her and herlover Dodi al-Fayed crashed in the Pont ​de L’Alma tunnel in Paris as it spedaway from chasing ​paparazzi photographers on motorbikes.

“Swan Song: Diana, My Sister”penned by ⁠her brother, known as Earl Spencer, is slated to bereleased next ​month in Britain and published around the world, telling thestory about Diana, from ​his perspective, according to its publisher Michael Joseph,a division of Penguin Random House.

“With the 30th anniversary of Diana’stragic death on the skyline, I’ve been inundated yet ​again with requests forinterviews about my sister,” Spencer said in a ​statement.

“This has convinced me to writedown my own thoughts and memories, once and for ‌all, ⁠rather than havingthe discomfort of again reading the opinions of others, many of which are basedon untruths that have become accepted over time.”

Diana became the most photographedwoman in the world after marrying Charles in ​a glittering ceremony ​in 1981.However, ⁠the marriage turned sour and they eventuallydivorced in 1996.

At her funeral, Spencer famouslydelivered a eulogy in which ​he castigated the royal family.

“The aim of this book ​is to ⁠tell the truthabout Diana from her brother’s perspective, just as I attempted to do whenspeaking at her funeral. As with my eulogy, I want ⁠to ​speak on Diana’sbehalf and do so ​in an openly positive way,” Spencer said.

Daniel Bunyard, Publishing Directorat Penguin Random House, said it ​would be a “book of historic importance”.