Shirley's family had a long connection with
County Monaghan in Ireland, and they owned a large estate at Lough Fea,
Carrickmacross. Shirley entered Parliament for
Monaghan (a seat previously held by both his father and grandfather) on 17 November 1868, and won election through a promise to defend the
Protestant constitution. He continued to represent the constituency until 31 March 1880, Shirley was also a
Deputy Lieutenant and
Justice of the Peace for County Monaghan and served as
High Sheriff of Monaghan in 1884. Although he was heavily involved in local affairs as initially guided by his father, and involved in improvements to the estate such as the construction of a new church in 1865, relations with the tenant farmers on his estates, which he inherited in 1882, remained poor. This, combined with forced evictions following the
agricultural depression of the 1880s, led to his estate being targeted by the Irish nationalist
Plan of Campaign. It also resulted in issues with the local railway, with a boycott by farmers of the station at
Carrickmacross taking place in 1890. ==Dog breeding==