Collector and numismatic dealer Richard Lobel hopes a museum will come forward to purchase the archive and place it on public display.
Lobel first became fascinated by Edward VIII, who abdicated in 1936 to marry the divorced American socialite Wallis Simpson, at the age of 13.
He made his first related purchase when he was 24.
“I am a romantic and I thought the story was just fantastic”, said Lobel, who came to the UK in 1968 having established his business Coincraft in 1955. “I have never collected coins as I felt it is not fair to my customers. So I picked Edward VIII.
“I want to sell now as I will be 79 on my next birthday and I would like to see it go to a museum – somewhere it can be displayed and added to. I spent 50 years putting it together and I would like it to live on.”
Lobel considers the ephemera element of the collection to be the “second best in the world (the finest is owned by the royal family)” and the medallic collection the “best in the world”.
The entire group, comprising hundreds of items of ephemera, paintings, busts, ceramics and medals, has an asking price of £6.5m.
The collection ranges from the announcement of Edward’s birth in 1894 in George V’s handwriting to Edward’s 1936 daybook where the word ‘Finis’ is written on the day of the abdication.
Lobel bought at auction and through private sales. Among his ‘best buys’ was the archives of the Chateau de Cande where the couple were married in June 1937 and items bought at Spink’s 2010 sale of the collection of Joseph S Giordano (author of Portraits of a Prince) which included medals and coins. Lobel said he bought 198 of the 250 lots and weeks later bought another large chunk at a sale at Morton & Eden.
Lobel added: “I am one of very few people in the world who has ever actually owned Edward VIII British coins and that got me listed in the Guinness Book of World Records. Those coins have long been sold, but my collection contains some extremely rare pulls from his original coinage dies.”
He will continue to add to his collection until he agrees a sale.