Complex sentence: At the outbreak of the revolutionary movements in 1848, when Pope Pius IX still appeared to be a Liberal and an Italian patriot, Bassi, filled with national enthusiasm, joined General Durando's papal force to protect the frontiers as an army chaplain.
Split into simpler sentences: At the outbreak of the revolutionary movements in 1848, when Pope Pius IX still appeared to be a Liberal and an Italian nationalist. As a result, Father Bassi, filled with enthusiasm, joined General Durando's papal force to protect the frontiers as an army chaplain.