Auximum (mod. Osimo), an ancient town in Picenum, situated on an isolated hill 8 m. from the Adriatic, on the road from Ancona to Nuceria. It was selected by the Romans as a fortress to protect their settlements in northern Picenum, and strongly fortified in 174 B.C. The walls erected at that period, of large rectangular blocks of stone, still exist in great part. Auximum became a colony at latest in 157 B.C. It often appears in the history of the civil wars, owing to its strong position. Pompey was its patron, and intended that Caesar should find resistance here in 49 B.C. It appears to have been a place of some importance in imperial times, as inscriptions and the monuments of its forum (the present piazza) show. In the 6th century it is called by Procopius the chief town of Picenum, Ancona being spoken of as its harbour.