tribes, who advanced from the south towards the north, following the Slovak rivers, peacefully integrating into the remnants of the local population. La Tène Period From around 500 BCE, the territory of modern-day Slovakia was settled by Celts, who built powerful oppida on the sites of modern-day Bratislava and Devín. Biatecs, silver coins with inscriptions in the Latin alphabet, represent the first known use of writing in Slovakia. At the northern regions, remnants of the local population of Lusatian origin, together with Celtic and later Dacian influence, gave rise to the unique Púchov culture, with advanced crafts and iron-working, many hill-forts and fortified settlements of central type with the coinage of the "Velkobysterecky" type (no inscriptions, with a horse on one side and a head on the other). This culture is often connected with the Celtic tribe mentioned in Roman sources as Cotini. Roman Period From 2 AD, the expanding Roman Empire established and maintained a series of outposts around and just south of the Danube, the largest of which were known as Carnuntum (whose remains are on the main road halfway between Vienna and Bratislava) and Brigetio (present-day Szőny at the Slovak-Hungarian border). Such Roman border settlements were built on the present area of Rusovce, currently a suburb of Bratislava. The military fort was surrounded by a civilian vicus and several farms of the villa rustica type. The name of this settlement was Gerulata. The military fort had an auxiliary cavalry unit, approximately 300 horses strong, modelled after the Cananefates. The remains of Roman buildings have also survived in Stupava, Devín Castle, Bratislava Castle Hill, and the Bratislava-Dúbravka suburb. Near the northernmost line of the Roman hinterlands, the Limes Romanus, there existed the winter camp of Laugaricio (modern-day Trenčín) where the Auxiliary of Legion II fought and prevailed in a decisive battle over the Germanic Quadi tribe in 179 CE during the Marcomannic Wars. The Kingdom of Vannius, a kingdom founded by the Germanic Suebi tribes of Quadi and Marcomanni, as well as several small Germanic and Celtic tribes, including the Osi and Cotini, existed in western and central Slovakia from 8–6 BCE to 179 CE. Great invasions from the fourth to seventh centuries In the second and third centuries AD, the Huns began to leave the Central Asian steppes. They crossed the Danube in 377 AD and occupied Pannonia, which they used for 75 years as their base