Arrows of Desire — Geoffrey Household

Far in the future, a group of dissidents fight to rebuild Britain...
It has been seven hundred years since the United Kingdom was destroyed. In the aftermath of a global cataclysm, the peoples of Europe banded together under a single flag, but the English refused to go along. Their resistance was rewarded with a genocide that wiped out half the population. The survivors resettled in North Africa, and Britain was declared uninhabitable. To celebrate the year 3000, the island is repopulated, to be ruled according to Federation law. But there are those in the underground determined to begin old battles anew. A barbarian king rides in the forests, drinking beer and promising to resist the Federation at all costs. In the new capital, a student takes a shot at the High Commissioner, nearly killing him with an ancient weapon known as a rifle. After seven centuries of silence, the British are ready to rise again.