The Duke of Windsor was told by Prime Minister Sir Winston Churchill he should not go to the Queen's coronation in 1953, historical documents reveal.
The coronation was on 2 June 1953 after other dates were ruled out
The former king, who abdicated to marry American divorcee Wallis Simpson, was urged to tell the press an ex-monarch could not attend a coronation.
The documents released by the National Archives at Kew also reveal detailed ministerial discussions over the event.
The 2 June was chosen to avoid a clash with the Derby horse racing event.
The prime minister and his Cabinet colleagues considered details of the event including seating, gifts for children and the threat of black market tickets being sold for the procession route.
The Duke of Windsor had abdicated the throne in 1936
Minutes taken by Cabinet Secretary Sir Norman Brook show Churchill contacted the duke in France in November 1952.
Sir Norman wrote that Churchill said: "Advised him not to come to coronation.
"He will say to press that it would not be consistent with usage for coronation to be attended by any or former ruler."
The duke, formerly Edward VIII before his abdication in 1936, did not attend the coronation.
The papers reveal the prime minister suggested Monday 1 June for the coronation.
He thought Friday 29 May was "unlucky" and 3 June was ruled out because it coincided with the Derby horse racing meet in Epsom, Surrey - a favourite of the Queen's.
His colleagues were concerned about preparations taking place over the weekend, so Churchill concluded: "Argument points to 2 June".
Even before her coronation one of the Queen's first concerns was to settle the question of who would succeed her, the documents show.
She wanted the Cabinet to make sure it would be her husband - the Duke of Edinburgh - or one of her then two children who were aged five and three at the time.