The two Ebbsfleets in Kent
I submitted a paper on this topic for publication on 2011-07-11. In it I
show that the name of the western Ebbsfleet (Ebbsfleet Valley, Ebbsfleet
International station) is an invention of the 17th century, indirectly inspired
by the name of the eastern Ebbsfleet. The latter name goes back to the 11th
century at least, and is probably identical with the Ypwinesfleot mentioned in the Anglo-Saxon Chronicle.
Full details will be added here when the paper is published.