Ansanus was a 4th-century Christian martyr and a member of the noble Anician family from Rome. Born in 284, he was raised in secret as a Christian by his nurse, Maxima. During the persecutions under Emperor Diocletian, he publicly declared his faith at the age of nineteen. Known as the Apostle of Siena, he traveled to the region to spread the Gospel, eventually facing execution in Monteaperti after surviving various tortures.