When the United Kingdom officially leaves the European Union, it will mark one of the biggest political and economic shifts to ever happen in modern Europe. For the last few years, many have been wondering if Brexit will even happen at all. The U.K. and the E.U. have certainly been taking their sweet time coming to terms of what their future relationship looks like — and at times, it’s felt like no resolution would be reached. But, after much back and forth and waiting ( and protesting, and waiting ), Brexit Day is finally here.