an important river in the north of England, formed by the union of the North and South Tyne, near the village of Warden, 2 miles above Hexham, in the county of Northumberland, whence it pursues an easterly course to its mouth at Tynemouth. It is about 35 miles in length, for the last 18 of which it forms the boundary between Northumberland and Durham. Its principal affluent is the Derwent, from the south. The towns of Newcastle and North and South Shields are on its banks, and it thus carries on a very extensive trade (see Newcastle and Shields). North Tyne rises on the border of Scotland, and flows first south and then east, till it receives the Reed, whence its course is S.E. to its junction with the South Tyne. Its length is about 40 miles. South Tyne rises near Crossfell in Cumberland, flows first N. to Haltwhistle, whence its course is eastward, till it meets the North Tyne, its entire course being about 45 miles.