The Isara, which was a branch of the Sequana, has its name preserved in the Celtic name of a place which was on it, named Briva Isarae. [BRIVA ISARAE
] The Celtic element Is
has become Oise,
the modern name of the river, which is the same word as the English Owse.
D'Anville says that the name Isara in the middle ages became Esia or Aesia.
Vibius Sequester mentions a river Esia which flows into the Sequana; but D'Anville suspects the passage to be an interpolation, though it is impossible to judge what is interpolation in such a strange book as Vibius Sequester. Oberlin, the editor of Vibius Sequester, maintains the passage to be genuine (p. 110). [G.L