[1] Born in Montefalco, Aristide Rinaldini studied at the seminary of the Vatican (1860–1862), Almo Collegio Capranica in Rome (1862–1868), and the Pontifical Gregorian University, where he obtained his doctorate in philosophy and licentiate in theology.

He remained in Belgium as a "private agent" after the liberal cabinet of Prime Minister Walthère Frère-Orban broke diplomatic relations with the Holy See and Nuncio Serafino Vannutelli left for Rome.

He returned to Italy when made Substitute of the Vatican Secretariat of State on 31 May 1893 and remained in that position for three years.

On 14 August 1896 Rinaldini was appointed Nuncio to Belgium and Titular Archbishop of Heraclea in Europa by Pope Leo XIII.

He received his episcopal consecration on 30 August from Cardinal Mariano Rampolla, with Bishops Guglielmo Pifferi, OSA and Vincenzo Veneri (Rinaldini's own cousin) serving as co-consecrators.