The conspiracy of Gaius Calpurnius Piso (65 CE) represented one of the major turning points in the reign of Nero (54-68 CE). Piso intended to have Nero assassinated and to have himself declared Emperor of Rome by the Praetorian Guard. He enlisted the aid of several prominent Senators with a loosely conceived plan in which Faenius Rufus (joint colleague of Ofonius Tigellinus, heading the Praetorian Guard) would conduct Piso to the Praetorian Camp for a formal declaration by the Guard. Either through poor planning or lack of conviction the conspiracy was rapidly revealed and Nero ordered Piso to commit suicide. The philosopher Seneca and the poet Lucan were also implicated in the plot and dealt with in a similar fashion, but their complicity has never been precisely determined.
On January 24, 41 Caligula, his wife Caesonia, and their infant daughter Julia Drusilla were murdered by a conspiracy under Cassius Chaera.
Seneca attempted to convince the Senate that she was orchestrating a conspiracy against her son, but the reputation of the Emperor was damaged beyond repair by this case of matricide.
Hated by many citizens, with an increasing list of political enemies, Nero started to appreciate his loneliness, when in 65 he discovered the Pisonianconspiracy (named after Gaius Calpurnius Piso, who intended to take his place) and the involvement of old friends like Seneca in the plot.
Poppaea died in 66 A.D., and the next year Nero left Rome altogether for a tour of Greece, during which his extravagances alienated him further still from general citizens and military commanders alike.
More crucially, in his paranoia after the conspiracy he ordered a popular and successful general, Gnaeus Domitius Corbulo, to commit suicide, a decision which left other provincial leaders in doubt about his next move and inclined toward rebellion rather than inaction.
In 68 A.D. Vindex revolted in Lugdunensis, as did Clodius Macer in Africa.