English: In Henry IV Part 1, Hotspur has been promised England north of the River Trent on the success of his rebellion. To the irritation of his partners, he proposes extending this still further by diverting the river. Presumably he wants to cut out the Trent’s final bend north towards the sea at the Humber, giving him a large additional area of land, I think all or most in Lincolnshire.

This map shows how this could have been done, diverting the Trent into the nearby River Witham across the very low interfleuve between them. (A more southerly diversion direct to the Wash would give Hotspur still more land, but as the map shows this would require a much longer new channel.) Mortimer is unimpressed, and points out that the Trent’s upper course in the west (shown in yellow) already benefits him since it flows southwards there.

The purpose of the discussion in the play may be to highlight the chaotic, selfish nature of Hotspur’s plans for England: he intends to reshape his country to fit better with the promises the other rebels owe him, even at his partners’ own expense.

The Witham was indeed the lower course of the Trent before or during the Ice Ages (as once was a dry valley still further south, near Ancaster), but Shakespeare could not have known about this. A canal across the narrow barrier exists, on a slightly more northerly route to that shown here.

This image is adapted from the design ‘Major Rivers of England’. It is an approximate map, and should not be relied upon as part of your plans to overthrow the sovereign.