In Antiquity, Strongoli was the site of Petelia,[3] said to have been founded by Philoctetes.
It is the birthplace of Italian baroque composer Leonardo Vinci.
Some historians claim that Ancient Petelia already was a bishopric, established perhaps in 546 or then adopting the city's new medieval name Strongoli, but without solid evidence, and the see in never mentioned in the Byzantine imperial Notitia Episcopatuum of the Patriarchate of Constantinople, which most dioceses in Calabria belonged to in the 9th till 11th centuries, so its foundation may rather date from the Normans, probably late 12th century.
The first historical record of the Diocese of Strongoli (Curiate Italian) / Strongulen(sis) (Latin adjective) is a papal bulla from Pope Lucius III in 1183, naming it among the suffragans of the Archdiocese of Santa Severina (while confirming the Metropolitan's privileges).
Its Cathedral was the Church of Peter and Paul (chiesa dei Santi Pietro e Paolo), the episcopal city's only parish.
Yet between the 14th and 16th centuries, the diocese harbored a monastery of the Conventual Friars Minor (Santa Maria delle Grazie), an Augustinian convent (Santa Maria del Popolo), a Capuchin monastery (San Francesco d'Assisi) and some fifteen churches and chapels.[4]
On 1818.06.27 the see was suppressed, its territory being merged into the then Diocese of Cariati.
Tommaso de Rosa, ?Conventual Friars Minor (O.F.M.) (1342.11.13 – death 1351)
Alamanno (1351.05.30 –?)
Pietro (? –?)
Raimondo (? –?)
Paolo de’ Medici, ?Conventual O.F.M. (1374.07.14 –?)
Vito (1375.09.27 – 1385.04.28); next uncanonical Bishop of Tricarico (Italy) (1385.04.28 – 1399.11), then canonical Bishop of Tricarico (Italy) (1399.11 – death 1403)
Antonio (1389.06.18 –?)
Giacomo (1400.04.28 – 1402.10.09), previously Bishop of Anglona (1399.05.17 – 1400.04.28); later Bishop of Ales (Italy) (1402.10.09 – 1403.08.03), Bishop of Lavello (1403.08.03 –?)
Pietro (1407.07.23 – death 1413)
Antonio de Podio (1418.03.09 – 1429.12.23), previously uncanonical Bishop of Bosa (Italy) (1410.05.23 – 1418.03.09); later Metropolitan Archbishop of Santa Severina (Italy) (1429.12.23 – death 1453)
Tommaso Rossi (1429.12.23 – death 1433), previously Bishop of Cerenzia (1420.12.23 – 1429.05.18), Bishop of Oppido Mamertina (Italy) (1429.05.18 – 1429.12.23)
Domenico Rossi (1433.12.14 – death 1470)
Nicola Balestrari (1470.03.11 –?)
Giovanni di Castello (1479.04.21 – 1486.05.10), next Bishop of Carinola (Italy) (1486.05.10 – death 1501?)
Ferdinando Ughelli, Italia sacra, vol. IX, second edition, Venice 1721, coll. 516-525
Vincenzio d'Avino, Cenni storici sulle chiese arcivescovili, vescovili e prelatizie (nullius) del Regno delle Due Sicilie, Naples 1848, pp.141–142
Giuseppe Cappelletti, Le chiese d'Italia della loro origine sino ai nostri giorni, vol. XXI, Venice 1870, pp.263–267
Domenico Taccone-Gallucci, Regesti dei Romani Pontefici per le chiese della Calabria, Rome 1902, pp.446–447
Andrea Pesavento, La chiesa dei SS. Pietro e Paolo di Strongoli da Cattedrale a Collegiata, published in La Provincia KR nr. 8-10/1998
Paul Fridolin Kehr, Italia Pontificia, X, Berlin 1975, p.135
Norbert Kamp, Kirche und Monarchie im staufischen Königreich Sizilien, vol 2, Prosopographische Grundlegung: Bistümer und Bischöfe des Königreichs 1194 - 1266; Apulien und Kalabrien, Monaco 1975, pp.908–910
Pius Bonifacius Gams, Series episcoporum Ecclesiae Catholicae, Leipzig 1931, pp.927–928