Catilina, Piso, and their fellows entered readily into any plan which gave the prospect of proscriptions and cancelling of debtor-books; the former had moreover special hostility to the aristocracy, because it had opposed the candidature of that infamous and dangerous man for the consulship.
As he had formerly in the character of an executioner of Sulla hunted the proscribed at the head of a band of Celts and had killed among others his own aged father-in-law with his own hand, he now readily consented to promise similar services to the opposite party.

A secret league was formed.

The number of individuals received into it is said to have exceeded 400; it included associates in all the districts and urban communities of Italy; besides which, as a matter of course, numerous recruits would flock unbidden from the ranks of the dissolute youth to an insurrection, which inscribed on its banner the seasonable programme of wiping out debts.
Failure of the First Plans of Conspiracy In December 688--so we are told--the leaders of the league thought that they had found the fitting occasion for striking a blow.
The two consuls chosen for 689, Publius Cornelius Sulla and Publius Autronius Paetus, had recently been judicially convicted of electoral bribery, and therefore had according to legal rule forfeited their expectancy of the highest office.

Both thereupon joined the league.

The conspirators resolved to procure the consulship for them by force, and thereby to put themselves in possession of the supreme power in the state.