Knights of God (1987)

In the year 2020, Britain is divided into North and South. The Royal Family has been deposed and in its place rule the Knights of God, a harsh militaristic religious order headed by Prior Mordrin. But a rebel movement is growing, in spite of Mordrin's brainwashing "re-education" camps, and joining it are two love-struck teenagers, Gervase and Julia, who escape from one of the camps to join a quest to find the rightful King of England, and thus re-establish democracy and order to the land.