Lucius Cassius Longinus (praetor 66 BC)

Lucius Cassius Longinus (c. 106 – after 63 BC) was a Roman politician and a participant in the conspiracy of Catilina.

As praetor in 66 BC, Longinus prevented the trial of an unruly tribune of the previous year, Gaius Cornelius, from taking place.

He then joined the conspiracy of Lucius Sergius Catilina, another failed candidate, to overthrow the government.

Longinus conducted secret negotiations with the Allobroges, and was entrusted with setting fire to the city on the outbreak of the conspiracy.

However, he seems to have suspected that the Allobroges were informants, and fled the city before the arrest and execution of his fellow conspirators.