Calabresi was born on 2 January 1925 in Sezze Romano, Italy, the fourth of six brothers.
[2] On 3 July 1969 he was named Titular Bishop of Fundi and Apostolic Delegate to the Red Sea Region.
[3] He was consecrated on 28 September 1969 by Vatican Secretary of State Cardinal Jean-Marie Villot.
On 27 June 1992 he was a co-consecrator when Jorge Mario Bergoglio, later Pope Francis, was made a bishop.
[5] He was a participant in the successful Vatican mediation between Argentina and Chile over the Beagle conflict.