Chronology of Catholic Dioceses:Notes on the Diocese of Civitate 1059/1062
The diocese of Civitate was erected in the XI century after the Council of Melfi (1059). Its first bishop was probably Amelgerio (1062- ). Nobody knows exactly the story of this Diocese. It is possible it was destroyed by Federico II di Svevia in 1229/1230, we only know that it was uninhabitated in the XIV century. The see was moved to San Severo in 1580 by pope Gregory XIII.
Website of the Province of Foggia
http://www.newadvent.org/cathen/13453b.htm
-Giulio Longo