The tower was named after an early castle constable, John de Lilburn, but may have been built under Thomas of Lancaster; it was intended as a high-status residence, 59-foot (18 m) high, 30 feet square with 6 feet thick walls, with a guardroom for soldiers on the ground floor.
The castle was ill-maintained and fell into disrepair and by 1534, when Roland de Velville was the castle constable, rain was leaking into most of the rooms.
A licence to crenellate - a form of royal authorisation for a new castle - was issued by Edward II in 1316, and a castle constable was appointed in 1319, charged with defending both the castle and the surrounding manors of Embleton and Stamford.
The fortification is built of local stone and concentric in design, featuring a massive gatehouse that probably once provided high-status accommodation for the castle constable and visiting dignitaries.
The governance of the city of Cardiff was finally reformed by an act of Parliament in the 1835, introducing a town council and a mayor, severing the link with the castle constable.
The substantial size of the gatehouse allowed it to be used for accommodation as well as defence and it was comfortably equipped on a grand scale, probably for the use of the castle constable and his family.
