William the Conqueror's victory at Hastings in 1066 inaugurated a systematic programme of castle-building across England unprecedented in the island's history. Within twenty years, hundreds of motte-and-bailey and stone fortresses had been planted across the landscape, serving as instruments of Norman colonial control over the conquered Anglo-Saxon population. This castle-building campaign fundamentally reshaped the physical environment in which English culture and literature would develop.

The Norman Conquest and its castles had a profound and lasting effect on the English language and its poetry, as Norman French vocabulary — including the word 'castle' itself — flooded into Anglo-Saxon English to create the hybrid Middle English that Chaucer would later write in. The colonial castle appears in the Anglo-Saxon Chronicle as a symbol of oppression; later English poetry was haunted by the memory of this displacement. The politics of castle and keep remained embedded in English verse through the medieval period.