The large volumes edited by Br Costanzo Cargnoni, I Frati Cappuccini. Documenti e testimonianze del primo secolo, 5 voll. in 6 tomi. Edizioni Frate Indovino, Perugia, 1988-1993) are remarkable for their broad scope and quantity of their contents. The historical and textual introductions for each document and section of documents render this corpus even more valuable.
The little collection here only has some letters written to, from or about Capuchins in the first two decades of their existence. This collection focuses on the relationship between the Capuchins and Italian reform up to the eve of the convocation of the Council of Trent.
The letters are transcribed from Italian or Latin editions.
You can download the compilation here (1.4 Mb)