Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
Sulla ventured, without consulting the burgesses
or jurymen, to pronounce sentence of death on twelve of the most
distinguished men, including magistrates actually in office and
the most famous general of his time, and publicly to defend these
proscriptions; a violation of the venerable and sacred laws of appeal,
which met with severe censure even from very conservative men, such
as Quintus Scaevola.
He ventured to overthrow an arrangement as to
the elections which had subsisted for a century and a half, and to
re-establish the electoral census which had been long obsolete and
proscribed. He ventured practically to withdraw the right of
legislation from its two primitive factors, the magistrates and the
comitia, and to transfer it to a board which had at no time possessed
formally any other privilege in this respect than that of being asked
for its advice.(26)