By the start of the 14th century, the Tenby town walls were mostly completed so diminishing the defensive importance of Tenby Castle. In 1328, they were further strengthened when a D-shaped barbican was built to defend the town's main gate and additional D-shaped towers were later added to the northern and southern walls. By the 1400s, the line of Earls had died out, and Tenby castle was abandoned and in disrepair.