During the 17th century, the comune of Palestrina was the family territory of a number of Italian noble families including the Barberini, Colonna and d'Este families (which regularly intermarried). Members of these families are represented throughout the list of diocese Bishops, especially between 1600 and 1800. Barberini Pope Urban VIII appointed a number of relatives and close supporters to the Palestrina diocese and governmental positions.
Like all dioceses in this category, for historical reasons it has had, since 1960, an incumbent residential bishop with ordinary powers but also has assigned to it as an honorary high ranking dignity one of the six cardinals in the Order of Cardinal Bishops. The Cardinal Bishop has no powers with regard to the government of the diocese.
cfr. Ivan Kuklujević Sakcinski: Codex diplomaticus regni Croatiae, Dalmatiae et Slavoniae, Vol. 1, Zagreb 1874, pp. 76-82; Regesta Imperii Online. Papstregesten 911-1024 Nr 70-73 and 111
Liudprandi historia Ottonis, MGH SS rer. Germ. 41, p. 165
cf. G. Cappelletti: Le chiese d'Italia della loro origine sino ai nostri giorni. Vol. 1, Venic 1844, pp. 599-601
Regesta Imperii Online. Papstregesten 911-1024 no. 758; and Papstregesten 1024-1046 no. 95
Sources for the period 1036-1130: Hüls, p. 108-117; Klewitz, p. 33-35, 117 and 120
Hüls, p. 111 no. 8 says that his existence is dubious because he appears only in one bull dated September 1092 which has been recognized as falsehood, though possibly based on original documents. Klewitz, p. 117 does not mention him among the occupants of this suburbicarian see.
Some sources mention cardinal Corrado 1105-1106 but the only document attesting his existence (bull of Paschalis II in favour of the church of S. Salvatore dated 27 December 1105) has been recognized as falsehood and both Klewitz, p. 120 and Hüls, p. 112-113, eliminated him from the list of the bishops of Palestrina
Source for the period 1130-1187: Brixius p. 135
Some sources mention cardinal Ugo or Ottone occupying that see ca. 1164 but Brixius, p. 60-68 excludes him from the list of cardinals created by Alexander III because no papal bulls signed by him has been found. Probably he is confused with cardinal-bishop Odo of Tusculum 1170-1171 (cf. Brixius, p. 65 no. 21)
Source for the period 1188-1228: Maleczek, p. 63
Some sources indicate that abbot Mainard of Pontigny became bishop of Palestrina in 1188 and died few weeks after his promotion but Maleczek, p. 125 says that Mainard is attested as abbot of Pontigny until 1192. Therefore, he should be excluded from the list of the bishops of Palestrina
Source for the list from 1231: The Cardinals of the Holy Roman Church
Some names in this list are from "Palestrina (Cardinal Titular Church)". Catholic-Hierarchy. Retrieved 2006-12-31.