Arrival of the Human's as Sahuagin Salves

Population Migration / Travel

The Sahuagin Empire brings human slaves from an unkown continent in the west to fight against the elves. Their origin is lost to history.
  The first human slave settlements are established along Sahuagin cities. Sahuagin use them as cheap cannon fodder against the elven armies and therefore encourge them spreading, keeping them under control by fear.