Original: Earthsea became the setting for a further six books, beginning with A Wizard of Earthsea, first published in 1968, and continuing with The Tombs of Atuan, The Farthest Shore, Tehanu, Tales from Earthsea and The Other Wind.
Simplified: The books that follow A Wizard of Earthsea are The Tombs of Atuan, The Farthest Shore, Tehanu, Tales from Earthsea and The Other Wind. These are all set in the world of Earthsea