Member of a Verona legal family, Caspar joined the diocesan seminary in 1796, the year when the French occupied much of northern Italy. He worked at tending the sick and the wounded before being ordained priest in 1800. He then became a parish priest for twelve years. His work was impeded by the French under Napoleon, who occupied much of Italy including the Papal States, and for a time held Pius VII a prisoner. Bertoni and his fellow priests and parishioners strongly supported the pope. During these difficult years he was a notable counsellor and spiritual director: one of his principal devotions was to the Passion, especially the five wounds of Christ.
After the defeat of Napoleon, Caspar founded in 1816–17 a religious association at Verona, which preached missions; this incurred the hostility of the Austrian government, now in control. So he turned instead to education in free schools, which he hoped would encourage religious vocations. This proved successful and in spite of his being bed-ridden for many years with considerable suffering, his congregation of the ‘Holy Stigmatics’ spread rapidly through many countries in western Europe, America, Africa, and parts of Asia. It now has 78 houses with several hundred priests. He was beatified in 1975 and canonized in 1989. Feast: 12 June.
Bibl. SS., iii. 117–8;B.L.S., vi. 99–100. Lives by N. dalle Vedove (1951 and 1960).