In the republican and early imperial periods, the right bank of the Tiber was occupied by the Ager Vaticanus (Plin. Nat. 3.53), which extended from a point facing the town of Fidenae to the north to the prata Quinctia facing the navalia, the river port, to the south (Livy 3.26.8; Plin. Nat. 18.20). From the 2nd century CE onward, sources use the toponym Vaticanum, …