A British Union flag from Brexit day celebrations lies in the grass in front of the Palace of Westminster in London, early Saturday, Feb. 1, 2020.

Video. Five years on, how has Brexit changed Europe?

"There was worry that this was the beginning of the end, or that the UK departure would sow division in Europe. In fact, the EU has been very united, very consistent in how it's handled Brexit," says Brigid Laffan, Director of the Robert Schuman Centre at the European University Institute.