Tiberius may have been at least partially responsible for Caligula becoming the man he was. After all, Tiberius pretty much wiped out Caligula’s mother and five siblings and then Caligula had to live on Capri with the old creep. “Good night, Gaius. Good work. Sleep well. I’ll most likely kill you in the morning.” Try living with that for a few years!
It was quite a family. Caligula’s aunt and her lover was executed for plotting to assassinate Tiberius (and presumably other family members) so that her lover could take over. Unlike in the BBC “I, Claudius”, Sejanus was executed by being strangled, not stabbed.