Illustrissimi

Illustrissimi ("To the Illustrious Ones") is a book written by Pope John Paul I when he was Patriarch of Venice. 
The book is a collection of letters which were first published in the Italian Christian paper "Messaggero di S. Antonio" between 1972 and 1975. They were reprinted in book form in Italy in 1976. 
The work was first published in English in 1978 when Cardinal Luciani was elected Pope, but it only reached the public after the death of John Paul I.
The letters.
The 40 letters in all are addressed to people in Italian history and fiction, including