Julio-Claudian dynasty reign as being strongly influenced by his mother Agrippina, his tutor Seneca, and the Praetorian Prefect Burrus, especially in the first year. He was made Emperor over his step-brother, Claudius' son Britannicus, who he had killed. Agrippina was believed to have poisoned Claudius, having allegedly poisoned her second husband Gaius Sallustius Crispus Passienus. She had also arranged the deaths of Caligula's third wife, Lollia Paulina and Messalina's mother Domitia Lepida the Younger. She saw that the dynasty's numbers dwindle with the execution of Marcus Junius Silanus Torquatus, a grandson of Julia the Younger, to strengthen Nero's claim, having previously arranged
Emperor Kang of Jin empress. Later in 343, Emperor Kang's other uncle, Yu Yi (庾翼), proposed a major military campaign against Later Zhao, in coordination with Former Yan's ruler Murong Huang and Former Liang's ruler Zhang Jun, both nominal Jin vassals. Most officials feared this large undertaking, but with support from Yu Bing, Huan Wen (Emperor Kang's brother-in-law, having married his sister Sima Xingnan (司馬興男) the Princess Nankang), and Sima Wuji (司馬無忌) the Prince of Qiao, Emperor Kang approved the plan and mobilized troops. Yu Bing was made a governor to coordinate with Yu Yi, and He Chong was recalled to replace him, and