Serf's Turf was a virtual representation of one of Ezio Auditore da Firenze's genetic memories, relived by Desmond Miles in 2012 through the Animus.
Ezio Auditore received a contract from Niccolò Machiavelli to assassinate the guards responsible for extorting the Roman farmers.
Ezio assassinated the guards, thus liberating the farmers in Rome from the Borgia injustice.
Ezio assassinating one of the guards
Ezio assassinating another guard