In 1967 Uskela and part of Halikko were merged to the rapidly growing Salo which needed more area.

Uskela is the oldest parish in eastern Finland Proper, having been established sometime in the 13th century.

In the 16th century, Uskela was administratively a part of Halikko, but remained a separate parish.

[1] Salo was originally an important village within the parish, but became an epäitsenäinen kauppala (a market town that was not a separate administrative unit) in 1887 and a municipality in 1891.

It replaced a parish church founded in the Middle Ages dating from approximately 1440.