The Most Holy Kingdom of Italy and Mediterranean Bishoprics

The rulership of The Most Holy Kingdom is bestowed by God to Patriarch of Rome Sebastián II. On a smaller scale, the other 4 provinces of Barcelona, Sicily, Milan, and Sardinia with Corsica  are ruled by Bishops that follow orders from the Patriarch and from God. These provinces collect taxes, tariffs and other payments in the style of Late Medieval Mercantilism, and add them to the Holy Coffers.

Despite the prosecution of Christians by Diocletian, Christianity established itself as the dominant religion in the failing Roman Empire.  By the time of the division of the Empire and sackings of Rome, most of the Italian peninsula was prominantly Christian.  In the 5th Century, the first Pope confirmed his authority as the head of the Ostrogoths in Italy.  During the Byzantine occupation of Italy in the 7th century, the Popes assumed the role of authority in Rome and later the surrounding provinces.  In 751, the Lombards invaded vast territories of Italy. The Holy See pleaded with the Franks to protect them, and in 756 a Frankish army defeated the Lombards. This gap in central Italy was established as land of the new Papal States.  The Papacy slowly conquered the naval powers of Italy, with Tuscany in 1102and Amalfi in 1132, aided by the troops of the growing Roman Empire. This mercantile power power led to a larger navy and even more monetary power of the Holy See.
In 1189, the Roman Empire finished the Third Crusade, and with all remaining Pentarchs restored, people began to fear that the fledgling Papacy would loose it's power amongst the other Pentarchies.  In 1192, Furio's War was set off. This conflict was between Loyalists of the Pope, who believed that the Papacy should call upon Western Europe to reclaim these Pentarchies in the name of the true faith, and the Isidorites, that believed the Roman Empire was destined to conquer Italy.  The war ended in 1221 with a status quo, but these internal conflicts and those that followed signified a low point in Papal power.
1392 is likely the most important year in the history of the Papacy and even the Holy Kingdom of Italy.  Pope Leo IV, after anither devastating civil war, requested a summit to finally mend the Great Schism.  It was decided that the Pope should be renamed as the Patriarch of Rome, with religious juristdiction over Western Europe.
With the Great Schism mended, trade between Christian nations prospered. With this influx of money and population, the now-Holy Kingdom of Rome quickly conquered the remaining Italian territories, aided by Roman volunteers.  By 1413, Italy was under Pentarchal control, now as the Holy Kingdom of Italy.  Under the reign of Patriarch Sebastian I, strategic Iberian territories were conqured, along with a brief presence in North Africa.  However, upon his death, there was no strict governance of these territories, and the 3 Year's Rebellion occured, ending the presece in Africa. At the end of it, these territories in both Italy and Iberia were divided as seperate Bishoprics under the Pentarch of Rome.