 Nero claimed that Britannicus died from an epileptic seizure , but ancient historians all claim Britannicus ' death came from Nero 's poisoning him . Supposedly , he enlisted the services of Locusta , a woman who specialized in the manufacture of poisons . She devised a mixture to kill Britannicus , but after testing it unsuccessfully on a slave , Nero angrily threatened to have her put to death if she did not come up with something usable . Locusta then devised a new concoction that she promised would " kill swifter than a viper . " 
 Nero claimed that Britannicus died from an epileptic seizure , but ancient historians all claim Britannicus ' death came from Nero <a href='null_genetive' title='1'><mark>'s</mark></a>poisoning him . Supposedly , he enlisted the services of Locusta , a woman <a href='null_relcl' title='2'><mark>who</mark></a>specialized in the manufacture of poisons . She devised a mixture to kill Britannicus , but after testing it unsuccessfully on a slave , Nero angrily threatened to have her put to death if she did not come up with something usable . Locusta then devised a new concoction that she promised would " kill swifter than a viper . " 
Nero claimed that Britannicus died from an epileptic seizure , but ancient historians all claim Britannicus ' death came from Nero  poisoning him . Supposedly , he enlisted the services of Locusta , a woman specialized in the manufacture of poisons . She devised a mixture to kill Britannicus , but after testing it unsuccessfully on a slave , Nero angrily threatened to have her put to death if she did not cum up w/ something usable . Locusta then devised a new concoction that she promised would " kill swifter than a viper . "