The Gauls crossed the Alps and invaded northern Italy in the 4th and 3rd centuries BC, settling in the area that became known as Cisalpine Gaul (Gaul on this side of the Alps). Although named after the Gauls, the region was mostly inhabited by indigenous tribes, namely the Ligures, Etruscans, Veneti and Euganei. Estimates by Beloch and Brunt suggest that in the 3rd century BC the Gaulish settlers of north Italy numbered between 130,000-140,000 out of a total population of about 1.4 million. According to Pliny and Livy, after the invasion of the Gauls, some of the Etruscans living in the Po Valley sought refuge in the Alps and became known as the Raeti. The Raeti inhabited the region of Trentino-Alto Adige, as well as eastern Switzerland and Tyrol in western Austria. The Ladins of north-eastern Italy and the Romansh people of Switzerland are said to be descended from the Raeti.