Tiberius shared in Augustus's tribune powers as of 6 BC, but shortly thereafter went into retirement, reportedly wanting no further role in politics while he exiled himself to Rhodes. No specific reason is known for his departure, though it could have been a combination of reasons, including a failing marriage with Julia, as well as a sense of envy and exclusion over Augustus's apparent favouring of his young grandchildren-turned-sons Gaius and Lucius. (Gaius and Lucius joined the college of priests at an early age, were presented to spectators in a more favorable light, and were introduced to the army in Gaul.)