LAVINIIUM, an ancient city of Latium, founded by Æneas in honour of his wife Lavinia, between Laurentum and Ardea. At first it retained its importance, probably as a religious centre, in opposition to the claims of Alba, but it sunk after the fall of that city. Although on friendly terms, it seems, along with Laurentum, to have retained a certain measure of independence. In the time of Trajan, under the name of Lauro-Lavinium, it united with Laurentum, and flourished for a few years.