At midnight on New Year's Eve 1973, a British flag was raised in front of then-European Economic Community building in Brussels marking the start of the United Kingdom's full membership of the project. That day, British Prime Minister Edward Heath said membership would bring prosperity to his country.

On Monday, almost one year after UK voters decided to leave this 28-member and 500-million-citizen bloc, British negotiators walked into the European Union headquarters to begin talks with their Brussels counterparts on the terms of their divorce.

This is just the beginning of a technically, judicially and financially extraordinarily complex series of negotiations, which aim to end the interdependence formed by many treaties, laws and projects.