Pius Was adopted by the emperor Hadrian and is widely regarded as one of the five good emperors, he succeeded to the principate after the death of Hadrian, he received the name Pius either as a result of his fight with the Senate to ensure the deification of Hadrian after his death, or his pardoning of Senators Hadrian had sentenced to death.
His reign was characterised as one of the most peaceful in the entire period of the principate, although there were some military actions during his reign they were located away from the capital and none were particularly serious.
Pius expanded access to drinking water for the people of Rome and suspended taxes for regions that had suffered natural disasters and offered inducements to see damaged cities rebuilt.
Two nights before his death he ate Alpine cheese at dinner quite greedily. In the night he vomited; he had a fever the next day. The day after that, 7 March 161, he summoned the imperial council, and handed the state and his daughter to Marcus Aurelius before dying at the age of 74 having been emperor for 23 years.