Wikipedia
Callixeinus was an Athenian politician who lived around 400 BCE, the time of Socrates. In the political aftermath of the Battle of Arginusae, Callixeinus was a lead instigator in the en masse trial and execution of six generals, including Thrasyllus and Pericles the Younger, son of Aspasia and Pericles.
After aggressive lobbying by Callixeinus, the generals were found responsible for not saving the sailors left adrift after the battle. Socrates, as member of Heliaia, refused to be cowed by threats of impeachment and imprisonment and blocked the vote until his Prytany ended the next day, whereupon the six Generals were condemned to death.
Public blame towards the generals for the incident soon turned to regret for the executions, and Callixeinus fled Athens. Several years later, he returned only to die of starvation.