After Antoninus died in 161, Marcus was effectively sole ruler of the Empire. The formalities of the position would follow. The senate would soon grant him the name Augustus and the title "imperator", and he would soon be formally elected as "Pontifex Maximus", chief priest of the official cults. Marcus made some show of resistance: the biographer writes that he was 'compelled' to take imperial power. This may have been a genuine "horror imperii", 'fear of imperial power'. Marcus, with his preference for the philosophic life, found the imperial office unappealing. His training as a Stoic, however, had made the choice clear to him that it was his duty.