Why did Tiberius rule after Augustus?

Tiberius ruled after Augustus because he was the stepson and designated successor of Augustus, the first Roman Emperor. Augustus adopted Tiberius as his son, ensuring a smooth transition of power within the Julio-Claudian dynasty. After Augustus's death in AD 14, Tiberius ascended to the throne, continuing the policies and governance style established by his predecessor. His rule marked a shift towards a more autocratic form of governance, which would define the imperial system in Rome.