Silanus was a descendant of the noble Roman house of the
Junii Silani. He was probably the son of
Decimus Junius Silanus, consul in 62 BC, (thus the grandson of
Marcus Junius Silanus, consul in 109 BC.) and
Servilia, mistress of
Julius Caesar, (thus the half brother of
Brutus the Younger, full brother of
Junia Prima,
Junia Secunda and
Junia Tertia and the brother-in-law of
Marcus Aemilius Lepidus, the triumvir, through Secunda. Silanus was possibly the same man who served as one of
Julius Caesar's
legates in 53 BC. He supported his brother-in-law Lepidus in 44 BC after Caesar's murder, accompanying Lepidus over the
Alps. The following year, Lepidus sent him with a detachment of troops to join
Marcus Antonius at
Mutina, but refused to accept responsibility for the help which Silanus gave. After falling out of favor with the
triumvirs, in 39 he fled to
Sextus Pompeius. He was able to return to Antonius's service under the terms of the
Pact of Misenum. A Silanus later served under Antonius in
Achaea and
Macedonia from 34 to 32, with the title of
Quaestor pro consule or perhaps
Proquaestor. Although the inscription in Achaea names a Silanus whose parents were named Marcus and Sempronia. Around this time he was also elected as an
Augur. Before the
Battle of Actium, Silanus went over to Octavianus. The future emperor raised him to the
Patriciate in 30 BC, and they held the consulship together in 25. Marcus may have married a woman named Manlia from the
Manlii Torquati, based on his descendants names. Silanus' grandson,
Marcus Junius Silanus Torquatus, was consul in AD 19, and married a great-granddaughter of Augustus. ==See also==