The sectarian violence in Derry during June 1920 was a volatile precursor to the broader political and social unrest that would envelop Northern Ireland in the years to come. Following the partition of Ireland in 1920, Northern Ireland was established as a distinct entity with a predominantly unionist government that favored Protestant interests. Derry, historically a divided city, experienced escalating tensions between its Catholic nationalist residents who sought unity with the Irish Republic and the Protestant unionist community keen on remaining part of the United Kingdom. The week of violence began on June 18, driven by long-standing grievances over jobs, housing, and political representation.

The violent clashes erupted on the streets, leading to arson, rioting, and assaults, with both sides suffering casualties. Hundreds were displaced as homes were burned and businesses vandalized. The crisis was exacerbated by the presence of paramilitary groups who were eager to defend their communities, further entrenching the divide. Local leaders attempted to mediate, but mistrust and animosity overshadowed their efforts, leading to an atmosphere rife with fear and hostility.

This week of violence in Derry did not just reflect local tensions; it signaled the beginning of widespread sectarian conflict that would define Northern Ireland for decades. In the aftermath, the Government of Northern Ireland established policies aimed at maintaining order, yet they often deepened existing divisions. The recurrence of such violence would contribute significantly to what would later be known as The Troubles, a period characterized by significant civil unrest and conflict between nationalist and unionist paramilitary groups that lasted for thirty years.