Nevertheless, the possibly first commander of the "tagma", Strategios Podopagouros, was among the leaders of a failed plot against Constantine V's life in 765, and was executed after its discovery. This initiated a purge of the new units from suspected opponents of the Emperor's policies. By the 780s, however, following years of imperial favour and military victories under Constantine V and his son Leo IV the Khazar (), the "tagmata" had become firm adherents to the iconoclast cause. Within less than two months of Leo V's death in 780, Empress-regent Irene of Athens had to foil an attempt spearheaded by the Domestic of the Excubitors to place Constantine V's exiled second son, Nikephoros, on the throne, and in 785/6 Irene forcibly disarmed them and exiled some 1,500 tagmatic soldiers due to their resistance to the restoration of the icons.