Hadrian executed his architect, Apollodormus of Damascus because he made fun of a temple he created. Remember, never make fun of anything that belongs to a very powerful person!
A month or so after Commodus' death, Hadrian adopted Antoninus Pius, a respected senator, on the rule that Antoninus, who didn't have any kids, would adopt Hadrian's nephew, Marcus Aurelius and Lucius Verus (the son of Commodus) as heirs.