Scotland during the Roman Empire of the geography of Scotland had extended to the "Hebudes" (The Hebrides), "Dumna" (probably the Outer Hebrides), the Caledonian Forest, and the Caledonians. Ptolemy, possibly drawing on earlier sources of information as well as more contemporary accounts from the Agricolan invasion, identified 18 tribes in Scotland in his "Geography", but many of the names are obscure. His information becomes much less reliable in the north and west, suggesting early Roman knowledge of these area was confined to observations from the sea. Famously, his coördinates place most of Scotland north of Hadrian's Wall bent at a right angle, stretching due eastward
Newcastle town wall town wall was constructed during the 13th and 14th centuries to repel Scottish invaders. Newcastle is about from the River Tweed, which marks the border between England and Scotland, as it did then. At that time there was a power struggle between England and Scotland, that eventually led to the Wars of Scottish Independence. The Scottish kings were always ready to take advantage of any weakness in the English rule to invade the North of England. An example of this is David I of Scotland, who took advantage of the civil war between Stephen and Matilda to invade Northumberland in