From modest beginnings in 1957, the EU has since evolved both by deepening – adding new tasks and responsibilities to the Commission’s remit – and by widening – adding new members in a series of accessions, to arrive at the present 28 member states. A new complication was the UK’s referendum in June 2016 that opted for Brexit. The EU’s evolution by enlargement is examined, followed by an outline of the major EU institutions and the links between them. This includes EU engagement with the wider world via trade deals and aid. The suitability of the EU’s acquis for applicant states and countries in the EU neighbourhood is reviewed, followed by an assessment of the overall EU ‘Model’. Having appeared to function well and deliver significant benefits to the member states, the ‘Model’ has performed far less well since the 2007–2009 financial crisis, revealing major weaknesses in the Union’s capabilities. The EU needs new, more flexible economic models, as well as new modes of engagement, both internally and with its various partners. In addition, the EU’s political model needs reform, both to deal with the democratic deficit and to provide for more effective decision-making.