The emperor Commodus was generally disliked. On the 31 of December, 192 AD, he was assassinated. The City Prefect of Rome, P. Helvius Pertinax, succeeded him, coming to power on 1 January, 193 AD. Three months later he too was murdered. Didius Julianus was the next emperor. Julianus had been a rich senator. After Pertinax's assassination, he saw his opportunity for power and seized it by means of a huge bribe to the praetorian guard (25,000 sesterces to each member). In April of 193 AD, though, two would-be emperors declared their bids for power. These were G. Pescennius Niger, legate of Syria, and Septimius Severus, legate of Pannonia. Severus, supported by the senate, overthrew Julianus (who was executed on the second of June) and then defeated Niger by crossing the Sea of Marmara and winning battles at Cyzicus and Nicaea. The final battle was won at Iussus. Terrified, Niger attempted to escape in Antioch, but he was captured and killed. The Parthian Wars ensued and resulted in more Roman conquests. Severus then proceeded to defeat Clodius Albinus, the governor of Britain and a former ally. Four years of civil unrest were ended by a final defeat of Albinus outside Lyon in February 197 AD.