Great Lions of the Past

The Great Kings of the Past, according to Mufasa, are deceased rulers of the Pride Lands, who look down on the living beings from the stars. While it is commonly believed that the lions in The Lion King Believe the stars themselves are the Great Kings of the Past, it was never actually confirmed in the film.

The Lion King
After Mufasa briefly plays with Simba after scolding him for his disobedience, Simba cheerfully tells Mufasa that they will always be together. However, Mufasa tells Simba about the Great Kings of the Past, who are former monarchs of the Pride Lands who look down on the living. Mufasa later tells his son that when he feels alone, the Great Kings will always be there to guide him, and so he, one day.

The Great Kings of the Past are mentioned in the film again by Simba when he, Timon, and Pumbaa offer up their theories of stars. Timon mocks what Mufasa told Simba and indirectly calls Mufasa "a mook."

The Lion King II: Simba's Pride
After the rhino chase, Kiara and Kovu stargaze later that night. Kiara sees a constellation of a baby rabbit while Kovu sees a constellation of two lions fighting each other. Kovu enjoys this pastime, and states he's never done this before. Kiara states the great Kings of the Past are up there, indicating Simba told Kiara of what Mufasa told Simba when he was young. Kovu responds by wondering if Scar is one of the Great Kings of the Past.

The Lion Guard: Return of the Roar
The Great Kings of the Past control a great power called the Roar of the Elders, which is bestowed on the second-born cub of the monarch, who is also tasked with leading the Lion Guard. The Great Kings control this power's use and can take it away if the user does not respect their gift, as is the case with Scar.

When Kion receives the gift, he uses it to free his best friend Bunga from the clutches of two villainous hyenas. The Great Kings can be seen roaring alongside him in the clouds.