Franz Bonaventura Adalbert Maria Herzog von Bayern, his royal highness the Duke of Bavaria, is king of both Great Britain and France. At least, this closest descendant of Charles I has that distinction according to the Jacobites, who have never abandoned British claims to France. These claims can be traced back to 1340 and survived even when the Hanoverians replaced the Stuarts, until they were quietly dropped by George III in 1800, at the time of the Act of Union between England, Scotland and Ireland.

However, even those living in this genealogical cloud-cuckoo land never went so far as to envisage a physical union between France and the United Kingdom. Such a suggestion has only been made twice, on each occasion during a time of political and military catastrophe. In June 1940, with France on the point of capitulation, Winston Churchill offered union with the UK; but Marshall Petain sued for peace with Germany the very next day and the idea collapsed. We now know from recently released records of government meetings that it happened once more. At the time of the 1956 Suez crisis, the French Prime Minister, Guy Mollett, put forward a similarly unworkable proposition to the British cabinet.

Mollett visited London on 10 September 1956 and suggested a merger at a meeting with the British Prime Minister, Antony Eden, an ardent Francophile. Mollett went so far as to say that there was unlikely to be any objection to the Queen becoming French Head of State. Later that month it was suggested that France join the Commonwealth as a preliminary step towards union.

Some political observers accused Mollett of dangling this merger as bait to persuade Britain to collude with the French in recovering the jointly-owned Suez Canal, which had been nationalised by the ruler of Egypt, Gamal Abdel Nasser. On 21st October 1956, Mollet, Eden and Israel Prime Minister Ben Gurion met in secret and agreed to make a joint attack on Egypt. This proved a disastrous miscalculation, as the international community, led by the United States, forced them to withdraw. Eden had to resign and Mollett’s government collapsed in May 1957.

Mollett, the son of a textile worker, taught English at Arras Grammar School and spoke it fluently. He was a hero of the French Resistance during the Second World War; arrested three times and interrogated by the Gestapo, he never gave up his colleagues. A member of the French Socialist party, Mollett joined the National Assembly in October 1945 and became a government minister in 1946. He was appointed prime minister of a coalition government in January 1956 but never recovered from the Suez scandal and eventually retired from politics. He died in 1975. Whether, had the attack on Egypt proved a success, the French people could ever have been persuaded to agree to the union that Mollett and Eden espoused, seems extremely doubtful.