Year 435 BC was a year of the pre-Julian Roman calendar. At the time, it was known as the First year of the Consulship of Iullus and Tricostus (or, less frequently, year 319 Ab urbe condita). The denomination 435 BC for this year has been used since the early medieval period, when the Anno Dominicalendar era became the prevalent method in Europe for naming years.
A dispute arises between Epidamnus' oligarchs and democratic forces in the Greek colony. Most of the colony's inhabitants originate from Corinth or Corcyra (Corfu). Epidamnus' oligarchs are exiled and then appeal to Corcyra for help, while the democrats enlist the support of Corinth. Corcyra is then attacked by Corinth as the dispute heats up.