Thay is magocracy in eastern Faerûn bordered to the north by Rashemen. Thay is ruled by council of Zulkirs, eight powerful Specialist Mages representing each School of Magic. The Red Wizards of Thay, a powerful organization of mages serves as the ruling class of noblemen in Thayan society and appoints the Zulkirs. Thay is infamous for legalizing slavery.
Thay is often at war with its neighbours of Rashemen, taking conquered Rashemi people as slaves. This is the reason for the strong hatred between the two nations.
Edwin Odesseiron hails from Thay and it is strongly implied that he is a member of the Red Wizards. His plan to kill Dynaheir reflects the Thayan-Rashemi relations.
External links
Thay on the Forgotten Realms Wiki, a wiki for the Dungeons & Dragons campaign setting Forgotten Realms.