The Romans first began to conquer lands surrounding "Singidun" during the 1st century BC. In 75 BC, Gaius "Quintus" Scribonius Curio, the proconsul of Macedonia, invaded the Balkan interior as far as the Danube, in an effort to drive out the Scordisci, Dardanians, Dacians and other tribes. The Romans had victories during these campaigns, but only stayed briefly, leaving the area outside of Roman control. Thus, very little is known about these operations or when the area was organized into the province of Moesia. It wasn't until the rule of Octavian, when Marcus Licinius Crassus, the grandson of the Caesarian Triumvir and then proconsul of Macedonia, finally stabilized the region with a campaign beginning in 29 BC Moesia was formally organized into a province some time before 6 AD, when the first mention of its governor, Caecina Severus, is made. "Singidun" was Romanized to "Singidunum". It became one of the primary settlements of Moesia, situated between Sirmium (modern Sremska Mitrovica) and Viminacium (modern Kostolac), both of which overshadowed Singidunum in significance, and just across the Sava River from Taurunum, in Pannonia. Singidunum became an important and strategic position along the "Via Militaris", an important Roman road connecting fortresses and settlements along the Danubian "limes", or border. It became known as Limes Moesiae.