I have a suggestion for why the Thames is known as the Isis round Oxford.
A simple logical answer that I can find no support for in the literature.
It is well known that the current path of the Thames is not the ‘old’ river.
Look carefully to the left hand edge of the flood plain. The existing river flows West to East and then South to Oxford.
That faint line of streams you see from Wytham down is the ‘old’ river. The flood plain is higher to the East than it is to the West. By just a few feet but water doesn’t care. The new river is pushed East at every step. Held up by little walls and dams from King’s Lock down to Oxford and beyond.
The weir near Wytham has a higher ‘cill’ to the river/stream below than does King’s Lock which is where the river was moved Eastwards across to.
That ‘old’ river is now named as different streams all the way from Wytham in the North to Sandford in the South. All along the western edge of the flood plain.
Until quite recently that line of streams was the county boundary between Oxfordshire and Berkshire. An ancient line of boundary.
So the question arises. When the ‘old’ river WAS the Thames, what was the stream over which it was then diverted in 600AD or so called? I think it was ‘The Isis’.
Fits all the facts. Requires no great explanation. Occam’s Razor?
Flooding around King’s Weir and Pixey Mead, Wytham, from the west, 1947 – Britain from Above”
Title Flooding around King’s Weir and Pixey Mead, Wytham, from the west, 1947