High Quality Content by WIKIPEDIA articles! Tiberius Sempronius Gracchus (b.168-163 BC d.133 BC) was a Roman politician of the 2nd century BC and brother of Gaius Gracchus. As a plebeian tribune, his reforms of agrarian legislation caused political turmoil in the Republic. These reforms threatened the holdings of rich landowners in Italy. He was murdered along with many of his supporters, by members of the Roman Senate and supporters of the conservative Optimate faction.