The Epidii (Greek: Επίδιοι) were a people of ancient Britain, known from a mention of them by the geographer Ptolemy c. 150.
[1] Ptolemy does not list a town for the Epidii, but the Ravenna Cosmography (RC 108.4) mentions Rauatonium, which is assumed to be Southend.
[2] The name Epidii includes the P-Celtic root epos, meaning "horse" (c.f.
Alex Woolf suggests that the Epidii became the Dál Riata, but argues that they were Brittonic-speaking in Ptolemy's time.
[4] He also suggests that the Hebrides, called the Ebudae by Ptolemy, were named after the Epidii.