He held the powerful post of praetorian prefect of the East some time during the latter part of Maurice's reign, although by 602 he held the post of curator of the palace of Hormisdas (curator domus divinae) and the extensive imperial estates attached to it.
[2] Constantine's tenure as praetorian prefect was unpopular due to the stringent financial policies pursued by Maurice.
[3] Constantine played an important role in the turmoil that ended Maurice's reign in 602, brought about by the mutiny of the Danubian army.
[4][5] On the day after the riots, 22 November, Maurice, with his family and closest associates fled the capital before the advancing rebel army under Phocas, and crossed over to Chalcedon.
In a bid to secure the support of the Persian shah Khosrow II (r. 590–628), Maurice dispatched his eldest son and co-emperor, Theodosius, to the East, and sent Constantine Lardys to accompany him.