Canon of the Grosseto Cathedral, Chelli was a controversial figure, a republican and liberal priest who supported the provisional democratic government of Francesco Domenico Guerrazzi and opposed Pope Pius IX.

[1] An eccentric and controversial figure, Chelli published articles in the 1840s for the Corriere Livornese, openly praising Pope Pius IX and especially Leopold II of Tuscany, to whom he dedicated the 1846 book La Maremma personificata, on the occasion of the inauguration of the monument to the grand duke in Grosseto.

[3] Starting in 1858, Chelli worked to create a place in Grosseto for collecting writings and art objects, aimed at spreading knowledge to the public and assuming an educational role for all the inhabitants of the Maremma over the years.

Chelli decreed that in every church in the Diocese of Grosseto, a prayer should be recited in honor of King Victor Emmanuel II, a move frowned upon by the Pope, who upheld the appeal of his detractors and removed him from office.

[1][4][5] With the Unification of Italy in 1861, Chelli's political positions again put him in bad light within the ecclesiastical realm, as in his writings he advocated for a return to the early Church, completely detached from temporal powers and entirely separate from the state, which should be strictly secular.