[1][2][3] Matteo Gagliani was born in Naples, Italy.
[4] On 20 July 1693, he was appointed during the papacy of Pope Innocent XII as Bishop of Fondi.
[1][4] On 2 August 1693, he was consecrated bishop by Galeazzo Marescotti, Cardinal-Priest of Santi Quirico e Giulitta, with Prospero Bottini, Titular Archbishop of Myra, and Giovanni Battista Visconti Aicardi, Bishop of Novara, serving as co-consecrators.
[4] On 15 January 1703, he was appointed during the papacy of Pope Clement XI as Bishop of Sora.
[4] He served as Bishop of Sora until his death in September 1717.