[3] Born in Rome[4] to parents from Tocco da Casauria, Abruzzo,[4] Marsilio graduated in Philosophy[4] at the Sapienza University of Rome and taught Aesthetics, Museology and Marketing applied to Cultural Heritage at the Link Campus University.

In the 2008 election, Marsilio was elected to the Chamber of Deputies with The People of Freedom,[5] leaving the Silvio Berlusconi's party in December 2012 when he took part in founding the national-conservative party Brothers of Italy led by Giorgia Meloni.

[1] At the end of 2018, Ignazio La Russa advanced Marsilio's candidacy for the office of President of Abruzzo,[6] the native region of both his parents.

Despite Marsilio being born and raised in Rome, his candidacy gained support from the entire centre-right coalition, leading to his victory at the 2019 regional election.

[3] On 19 March 2019 Marsilio resigned from the Senate in favour of Nicola Calandrini, a member of Brothers of Italy.