F. J. North reminds us that the well defined geographical entity now called the Bristol Channel should, on historical grounds, be called the Severn Sea. This was the name used by Giraldus Cambrensis (1146?–1223) in his Topographic Hibernica of 1188 and by Roger Barlow in his A Brief Summe of Geographic of 1540, among other early writers. But with Bristol's rise to fame as a great seaport the name Bristol Channel came to be used and, as early as 1693 we find the name ‘Canal de Bristol’ on a French sea chart by H. Jaillot.

An unknown writer of 1578, whose Discourse was published in John Stow's Survey of London of 1598, in explaining why a site on the Thames instead of one on the Severn was chosen for the metropolitan city, stated that:

‘… the Thames both for the straight course in length and reacheth furthest into the belly of the land, and for the breadth and stillness of the water is most navigable up and down the stream…. The river openeth indifferently upon France and Flaunders, our mightiest neighbours, on whose doings we ought to have a bent eye and special regard…

… For the Prince of this Realm to rest and dwell upon Severn were to be shut up in a cumbersome corner, which openeth but upon Ireland only, a place of much less importance…’