The River Trent is one of the major rivers of England. Its source is in Staffordshire between Biddulph and Mow Cop. It flows through the Midlands until it joins the River Ouse at Trent Falls to form the Humber Estuary, which empties into the North Sea below Hull and Immingham.
The river historically marked the boundary between Northern England and Southern England. For example the administration of Royal Forests was different north or south of the river, and the jurisdiction of the medieval Council of the North started at the Trent. Although the rise of the identity of the Midlands has moved the boundary slightly some slight traces of the old division do remain.
The Trent is unusual amongst English rivers in that it flows north and also exhibits a tidal bore, known as the Aegir. At certain times of the year, the lower tidal reaches of the Trent experience a moderately large tidal bore up to five feet high. The Aegir occurs when a high spring tide meets the downstream flow of the river, the funnel shape of the river mouth exaggerates this effect, causing a large wave to travel upstream as far as Gainsborough, Lincolnshire, and sometimes beyond. The aegir cannot travel much beyond Gainsborough as the shape of the river reduces the aegir to little more than a ripple, and weirs north of Newark-on-Trent, Nottinghamshire stop its path completely.