Valentinian III's ascension to the throne of the Western Roman Empire marked a pivotal transition in the governance of the empire. Born to Galla Placidia and the emperor Constantius III, Valentinian was named emperor at a young age, necessitating a regency due to his minority. His mother, Galla Placidia, who had been the regent since his birth, effectively managed the imperial administration and held the reins of power during this period. Her rule helped stabilize the empire at a time when it faced numerous threats, both internal and external.

As the date approached for Valentinian III to officially assume the title of emperor, Galla Placidia concluded her regency in a ceremony that symbolized the transition of power. However, she did not withdraw from politics entirely; instead, she retained significant political influence. Galla Placidia was known for her intelligence and shrewdness, which she would continue to employ in the affairs of the court and in negotiations with other powers.

The early years of Valentinian's reign were crucial as he faced various challenges, including conflicts with rival factions and pressures from barbarian tribes. Galla Placidia's continued involvement in governance allowed for a degree of stability in this tumultuous period and helped pave the way for Valentinian III to learn the complexities of ruling an empire that was beginning to fragment under pressure from outside forces and internal dissent.