The Kent coast, on the extreme south east of the United Kingdom, is geographically the British mainland's closest proximity to continental Europe. It is from this coastline that European influence has spread since ancient times eg. the Roman invasions and the arrival of Christianity. This coastline has also been the first line of defence when under attack by hostile European forces. This area has recently undergone economic hardships and an influx of migrants via the European Union's policy of freedom of movement. This has led to a hardening of opinion towards the EU. In the referendum on EU membership in 2016, the area voted to leave.