The area passed through his family until the advent of the Normans in the 11th century.The castle was substantially altered and extended during the Victorian period by John Crichton-Stuart, 3rd Marquess of Bute, and the architect William Burges.It was likely made up of traders who made a living from the fort, ex-soldiers and their families. Contemporary with the Saxon Shore Forts of the 3rd and 4th centuries, a stone fortress was established at Cardiff.Similar to the shore forts, the fortress was built to protect Britannia from raiders.Archaeological evidence from sites in and around Cardiff – the St Lythans burial chamber, near Wenvoe (about four miles (6.4 km) west, south west of Cardiff city centre), the Tinkinswood burial chamber, near St Nicholas (about six miles (10 km) west of Cardiff city centre), the Cae'rarfau Chambered Tomb, Creigiau (about six miles (10 km) north west of Cardiff city centre) and the Gwern y Cleppa Long Barrow, near Coedkernew, Newport (about eight and a quarter miles (13.5 km) north east of Cardiff city centre) – shows that people had settled in the area by at least around 6,000 years before present (BP), during the early Neolithic; about 1,500 years before either Stonehenge or the Great Pyramid of Giza was completed.
This sound change had probably first occurred in the Middle Ages; both forms were current in the Tudor period.The unitary authority area's 2016 population was estimated to be 361,468 The Cardiff Urban Area covers a slightly larger area outside the county boundary, and includes the towns of Dinas Powys and Penarth.A small town until the early 19th century, its prominence as a major port for the transport of coal following the arrival of industry in the region contributed to its rise as a major city.In addition to serving an important political role in the governance of the fertile south Glamorgan coastal plain, Cardiff was a busy port in the Middle Ages due to its location on the Bristol trading routes, and was declared a Staple port in 1327.
This furthermore led to the town gaining a reputation for piracy, which by the Early Modern period led to much dispute between the burgesses of Cardiff and the surrounding county families.
Coins from the reign of Gratian indicate that Cardiff was inhabited until at least the 4th century; the fort was abandoned towards the end of the 4th century, as the last Roman legions left the province of Britannia with Magnus Maximus.