The Earth Kingdom ruler known as the Earth King in Ba Sing Se is Kuei. He is the monarch of the Earth Kingdom during Avatar: The Last Airbender and lives in the royal palace at the center of Ba Sing Se.
Kuei’s reign is heavily constrained by the Dai Li, the secret police responsible for controlling information and suppressing unrest. Their leader, Long Feng, keeps the king isolated and misinformed, allowing the government to maintain the city’s official claim that there is no war. Kuei is therefore a ruler with a grand title but limited awareness of events outside the palace.
The name Kuei is sometimes confused with Long Feng because both are closely tied to Ba Sing Se’s government. Long Feng is the political power behind the scenes, while Kuei is the legitimate monarch. Bumi is a different Earth Kingdom king: he rules the city of Omashu and is one of Aang’s oldest friends.