In August 1649, Oliver Cromwell arrived in Ireland with a Parliamentary army to crush the Catholic Confederation and reassert English control. The campaign was marked by brutal sieges at Drogheda and Wexford, where thousands of Irish soldiers and civilians were killed. The Cromwellian conquest effectively ended Catholic resistance and resulted in the wholesale confiscation of Catholic-owned land, entrenching Protestant ascendancy.

The Cromwellian conquest is a deeply traumatic event in Irish memory, invoked in poetry as a symbol of genocidal cruelty and colonial oppression. Poets from the Gaelic aisling tradition to 19th-century nationalists like Thomas Davis used the memory of Cromwell to rally resistance against British rule. The conquest's legacy of land confiscation and religious persecution became a recurring theme in Irish political poetry.