Their first foothold was on the shores of the River Tay.
Gradually growing more or less ruinous it was acquired by government in 1855, repaired, strengthened and converted into a Tay defence, mounting several heavy guns.
Before the erection of the Tay Bridge the town was the scene of much traffic, as the railway ferry from Tayport was then the customary access to Dundee from the south.
After conquering the Ordovices in North Wales and the island of Mona (Anglesey), during the next two years he carried his victorious arms to the Taiis (Tay; others read Tanaus, perhaps the north Tyne), and in his fourth campaign fortified the country between Clota and Bodotria (the firths of Clyde and Forth) as a protection against the attacks of the Caledonians.
The river flows out of Loch Earn, pursues an eastward course with a gentle inclination towards the south, and reaches the Firth of Tay, 62 m.