Glamorganshire, former county in south Wales; Cardiff was the county town. Glamorganshire comprised a hilly area in the north and a fertile lowland area, including the Gower Peninsula, in the south along the Bristol Channel. Glamorganshire was conquered by the Normans beginning in the late 11th century. It was made a county in 1536. The county's mineral wealth (especially coal) was exploited in the mid-19th century and was responsible for the growth of the towns of Port Talbot, Cardiff, and Swansea. In 1974 Glamorganshire was divided between the new counties of West Glamorgan, Mid Glamorgan, and South Glamorgan.