Bonhams is selling the contents of the late Lord Glenconner's property, 'Beau House', St Lucia, on Wednesday September 28 at New Bond Street, London.
The 3rd Lord Glenconner, formerly Colin Tennant, was best known for transforming the barren Caribbean island of Mustique into a luxurious and glamorous playground for the rich and famous.
Proceeds from the sale will benefit the Glenconner Trustees and Estate and, in the words of Bonhams, "reflect a man of taste, foresight and considerable philanthropy, with many objects providing insight into a way of life from a previous era."
The items from Princess Margaret particularly highlight the close links between the two families. Plenty of the items are estimated at entry-level values.
Lot 85 is a silver novelty snuff box by John Donald, London 1976, in the form of a book. The cover is engraved with a depiction of The Glen, the Glenconner family home in Scotland. The spine has a flush hinge and is engraved GLEN.
The gilt interior is engraved 'to Colin for your 50th birthday with Love from 'crowned' MR', length 6.5cm, weight 3.5oz. It is estimated to sell for £1,000-1,500.
Elsewhere in the sale, Lot 142 is a pair of double-sided cufflinks in green chalcedony spheres, presented to Lord Glenconner by Princess Margaret on another of his birthdays. They are estimated to sell for £1,000-1,500.
Margaret's diamond-studded tiara
While these items carry low estimates, the late Prince Margaret is no stranger to the higher end of the auction markets.
The recent Royal marriage of the Duke and Duchess of Cambridge wasn't the first to capture the public's hearts and minds. In fact, Princess Margaret's marriage to Antony Armstrong-Jones at Westminster Abbey was the first Royal wedding to be broadcast on television in May 1960.
Margaret's diamond-studded tiara for the occasion - originally made in 1870 by Garrard for Lady Poltimore, the wife of the second Baron Poltimore and Treasurer to Queen Victoria's household - sold for £926,400 at a Christie's auction in 2006.
- Learn how you can get pleasure and profit from Royal memorabilia
- Click here for all the latest Autographs and Memorabilia news
Join our readers in over 200 countries around the world - sign up for your free weekly Collectibles Newsletter today