When the Irish Civil War broke out in June 1922, O'Higgins tried to restore law and order by introducing tough measures. Between then and mid-1923, he confirmed the sentences of execution of seventy-seven republican prisoners of war, including Rory O'Connor who had been best man at his wedding. O'Higgins and his colleagues did not view them as prisoners of war, but rather as criminals. In reprisal for O'Higgins' role in the executions of captured republicans, the Anti-Treaty IRA murdered his father and burned his family home in Stradbally, County Laois.