Legio I Equestris was a Roman Army legion raised in Syracuse, Sicily by Sextus Pompeius in 43 BC. After the formation of the Second Triumvirate, Sextus raised the legion and rebelled against Octavian, Mark Antony, and Marcus Aemilius Lepidus, and all of Sicily flocked to his cause. Legio I Equestris was his only legion as of 41 BC, defending the entire island; Sextus instead relied on his naval power during his war with the triumvirs. It was destroyed by Octavian at the Siege of Syracuse in 40 BC.