Most people in Wales today regard themselves as modern Celts, claiming a heritage back to the Iron Age tribes. When the Roman legions departed Britain around 400, a Romano-British culture remained in the areas the Romans had settled, and the pre-Roman cultures in others. The people in what is now Wales continued to speak Common Brittonic with significant influence from Latin, as did people in other areas of western and northern Britain; this language eventually evolved into Old Welsh. The surviving poem "Y Gododdin" is in early Welsh and refers to the British kingdom of Gododdin with a capital at Din Eidyn (Edinburgh) and extending from the area of Stirling to the Tyne. Offa's Dyke was erected in the mid-8th century, forming a barrier between Wales and Mercia.