Original: The Kingdom of Sussex or Kingdom of the South Saxons was one of the Anglo-Saxon kingdoms, the boundaries of which coincided in general with those of the earlier kingdom of the Regnenses and the later county of Sussex.
Simplified: The Kingdom of Sussex, (Suth Seaxe, i.e. the South Saxons), was one of the Anglo-Saxon kingdoms, its area was more or less that of the later county of Sussex.