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 Yang of Sui Emperor Yang had Li Hun, Li Min, and their clansmen executed, and further poisoned Yang Lihua's daughter Yuwen Eying (宇文娥英). Later in 615, Emperor Yang carried out a tour of the northern provinces with the Empress Xiao and much of the imperial court. Shibi Khan, angered that the imperial advisor Pei Ju had promised a princess to his brother Ashina Chiji () and had executed his close advisor Shishu Huxi () under false pretenses, launched a surprise attack on Yanmen Commandery. In accordance with Turkish customs, Princess Yicheng had married him as her husband's successor; having been well treated by