Four People With Two Faces

The merchant Egeon of Syracuse had once been in a shipwreck. On that ship were his wife, their newborn twin sons, and two more twin babies bought to serve them. The people clinging to the broken hull were split into two groups and carried off on different seas.

Egeon was left with one son and one servant boy. The son was named Antipholus and the servant boy Dromio. The twins who were lost carried exactly the same two names.