Belisarius had been recalled in the face of renewed hostilities by the Persians. Following a revolt against the Empire in Armenia in the late 530s and possibly motivated by the pleas of Ostrogothic ambassadors, King Khosrau I broke the "Eternal Peace" and invaded Roman territory in the spring of 540. He first sacked Beroea and then Antioch (allowing the garrison of 6,000 men to leave the city), besieged Daras, and then went on to attack the small but strategically significant satellite kingdom of Lazica near the Black Sea, exacting tribute from the towns he passed along his way. He forced Justinian I to pay him 5,000 pounds of gold, plus 500 pounds of gold more each year.