How did the loss of Oswald the Lucky Rabbit lead to the creation of Mickey Mouse?

In 1927, Walt Disney began producing a series of animated films featuring Oswald the Lucky Rabbit. While the series was successful, Disney faced significant financial and creative conflicts with his distributor, Charles Mintz.1

Ultimately, Mintz forced Disney out of the project by hiring away his animators and seizing control of the character, to which Disney did not own the rights. This loss served as a pivotal turning point in Disney's career. Determined to maintain creative control, Disney and his chief animator, Ub Iwerks, went back to the drawing board to develop a new character.12

By altering the appearance of the original rabbit design, they created a new character that became Mickey Mouse. Having learned from the experience with Oswald, Disney ensured he held the copyright to his new creation, which debuted in 1928 and eventually eclipsed the popularity of his predecessor.12