The only deity or demigod not invited to the wedding between King Peleus and Thetis was Eris, the goddess of strife and discord.
Eris, the goddess of Discord
Eris the spirit/goddess of strife and discord. She was upset because she was not invited to the wedding.
She was a trouble maker.
Eris, goddess of discord, threw a golden apple inscribed "To The Fairest" to the goddesses at the wedding of Peleus and Thetis because she was angry at not having been invited to the celebration. 3 goddesses laid claim to the apple, and their rivalry brought about the events which led to the Trojan war.
If you mean the wedding that happened before the War of Troy that sort of relates to it, then it is Eris. The wedding was between Peleus and Thetis, the parents of Achilles.
Allen
Peleus and Thetis didn't invite Eris to their wedding, so she sent the golden apple that she knew would cause a fight
No he was not.
Eris, the goddess of discord, was responsible for that apple. She threw it as revenge for not being invited to the wedding of Peleus and Thetis.
Eris, personification of discord, threw a golden apple with the words "To the fairest," at the wedding of Peleus and Thetis.
Achilles
Achilles.
It was at the wedding of Thetis and Peleus to which the golden apple "for the fairest" was found which Aphrodite, Hera, and Athena all fought over.