C-3PO is a protocol droid and a main character in the Star Wars universe. Before meeting Luke Skywalker, C-3PO originated from Tatooine where he was built by a young Anakin Skywalker to help his mother. Eventually, Anakin returned to Tatooine and C-3PO left with him, only to return years later after his mind was wiped. C-3PO later went on to assist Luke Skywalker and his allies and became friends with R2-D2. C-3PO and R2-D2 are the only characters to appear in all nine Star Wars films.