[5][6] Maurice had served as magister militum per Orientem, the commander of Byzantine forces in the East,[7] securing decisive victories over the Sassanian Empire.
[6] In 602 Maurice ordered the Byzantine army to winter beyond the Danube, causing troops exhausted by warfare against the Slavs to rise up, and declare Phocas their leader.
[5] Theodosius may have been at that time in the Sasanian Empire, on a diplomatic mission,[17] or, according to some sources, was later sent by Maurice to request aid from the Sassanian Emperor Khosrow II.
After surviving a storm, Tiberius and his family landed at Saint Autonomos, near Praenetus, 45 miles (72 km) from Constantinople, but were forced to stay there due to Maurice's arthritis, which left him bed-ridden.
They were captured by Lilios, an officer of Phocas, and brought to the Harbor of Eutropius at Chalcedon, where on 27 November 602, Tiberius and his four younger brothers were put to death, followed by Maurice himself.