“血腥星期日” (Bloody Sunday) refers to the events of January 30, 1972, in Derry, Northern Ireland. On this day, a peaceful civil rights march protesting against internment without trial was met with gunfire from British soldiers. Thirteen unarmed protesters were killed, and many others were injured, leading to widespread outrage. The incident significantly escalated tensions in the Northern Ireland conflict, also known as “The Troubles.” It prompted increased support for the Irish Republican Army (IRA) and intensified calls for civil rights and political change. The legacy of Bloody Sunday continues to impact Irish and British relations today.