"It's been a utilitarian relationship since 1973 and the emphasis was always on the economic dimension, not on the political one," said Pauline Schnapper, professor of contemporary British history at the Sorbonne University in Paris.
"The sentimental dimension is near non-existent."
Britain was against joining the European project when it was conceived after the Second World War in a spirit of reconciliation.
"We didn't feel vulnerable enough to join," said Anand Menon, a professor of European politics at King's College London.
Instead, Britain preferred to focus on its special relationship with the United States and the remains of its empire.
London nevertheless supported the push for closer integration on the European continent and wartime prime minister Winston Churchill memorably called for the creation of a "United States of Europe" in a 1946 Zurich speech.
But in the early 1960s, Britain's fortunes changed for the worse.
Its economic growth started lagging behind that of France and Germany, making the European single market on its doorstep seem an appealing option.
'I want my money back'
"The UK's leaders came to realise that the UK could not be outside what, by the 1960s, was fast becoming western Europe's leading organisation for economics, politics and non-traditional security matters," said Tim Oliver, lecturer at London's Loughborough University.
"The UK had to be inside it to shape it."
But joining the European project was not an easy task.
France's then-president Charles de Gaulle vetoed Britain's first application in 1961, seeing it as a "Trojan Horse" for the United States and doubting Britain's European spirit.
Another French veto followed in 1967 and the UK was only finally welcomed into the then European Economic Community (EEC) on January 1, 1973.
Unfortunately for Britain, the first oil crisis struck the same year and the much-hoped-for economic boost failed to materialise.
Nevertheless, 67 per cent of the British people voted to remain in the EEC in a 1975 referendum.
But the result did little to temper euro scepticism in Britain, with politicians of all stripes reluctant to defend the project and the first crisis was not long in coming.
London refused in 1979 to participate in the European monetary system, defending its national and fiscal sovereignty.
It then resisted initiatives to deepen political integration, reinforcing the criticism that Britain had "one foot in, one foot out" of the project.
Britain notably refused in 1985 to participate in the Schengen agreement for free movement, and in 1993 to join the euro.
Its anti-federalist approach was spelt out by prime minister Margaret Thatcher during a 1988 speech at the College of Europe in Bruges.
In it, she rejected the idea of a "European super-state exercising a new dominance from Brussels".
The Conservative leader had four years earlier finally won a rebate on Britain's contribution to the European budget, making the infamous demand: "I want my money back".
With deeper European political union in the 1990s, Britain's defiance towards Brussels accelerated, leading to the creation of the UK Independence Party (UKIP), which campaigned for the country's exit from the EU.
The party's success, particularly in the 2014 European Parliament elections when it topped the polls, pushed the Conservative-led government to harden its rhetoric.
The eurozone crisis, large-scale immigration from the EU and the refugee crisis of the past few years stoked the discontent, pushing prime minister David Cameron to call the June 2016 referendum.
For pro-Brexit supporters, the vote to leave the EU will mean Britain finally "taking back control" of its borders, laws and finances.
"They had a rather dreamlike situation since they were in the union, yet had opt-outs on a number of things," noted Pascale Joannin, executive director of the Robert Schuman Foundation, named after the French politician considered to be one of the "founding fathers" of the European Union.
"But now they will be outside the union's institutions without a voice, and they will have to adhere to a number of European regulations", he added.
The divorce deal approved by Britain and the European Union on Sunday sets the stage for the end of a nearly 46-year marriage of convenience, built on prudence rather than shared dreams.