The Dacian Wars (101–102, 105–106) were two military campaigns fought between the Roman Empire and Dacia during Emperor Trajan's rule. The conflicts were triggered by the constant Dacian threat on the Danubian province of Moesia and also by the increasing need for resources of the economy of the Empire. Trajan turned his attention to Dacia, an area north of Macedon and Greece and east of the Danube that had been on the Roman agenda since before the days of Caesar when the Dacians defeated a Roman army at the Battle of Histria. In AD 85, the Dacians swarmed over the Danube and pillaged Moesia and initially defeated the army that Emperor Domitian sent against them. The Romans were defeated in the Battle of Tapae in 88 and a truce was established. Emperor Trajan recommenced hostilities against Dacia and, following an uncertain number of battles, defeated the Dacian king Decebalus in the Second Battle of Tapae in 101. With Trajan's troops pressing towards the Dacian capital Sarmizegetusa Regia, Decebalus once more sought terms. Decebalus rebuilt his power over the following years and attacked Roman garrisons again in 105. In response Trajan again marched into Dacia, besieging the Dacian capital in the siege of Sarmizegetusa, and razing it. With Dacia quelled, Trajan subsequently invaded the Parthian empire to the east, his conquests expanding the Roman Empire to its greatest extent. Rome's borders in the east were indirectly governed through a system of client states for some time, leading to less direct campaigning than in the west in this period. Early clashes Since the reign of Burebista, widely considered to be the greatest Dacian king—who ruled between 82 BC and 44 BC—the Dacians had represented a threat for the Roman Empire. Caesar himself had drawn up a plan to launch a campaign against Dacia. The threat was reduced when dynastic struggles in Dacia led to a division into four (or five, depending on the source) separately governed tribal states after Burebista's death in 44 BC. Augustus later came into conflict with Dacia after it sent envoys offering its support against Mark Antony in exchange for "requests", the nature of which has not been recorded. Augustus rejected the offer and Dacia gave its support to Antony. In 29 BC, Augustus sent several punitive expeditions into Dacia led by Marcus Licinius Crassus Dives, the consul of the prior year, that inflicted heavy casualties and apparently