I don't think you can discuss the Early Middle Ages, otherwise known as the Dark Ages without talking about what we now call Venice, the oligarchy of which transplanted itself later into London, where it still resides to this day.

"The islands of the lagoons provided an invulnerable refuge, comparable to Switzerland during World War II, for Roman aristocrats and others fleeing the paths of Goth, Hun, and Langobard armies. Already between 300 and 400 A.D. there are traces of families whose names will later become infamous: Candiano, Faliero, Dandolo. Legend has it that the big influx of refugees came during the raids of Attila the Hun in 452 A.D. Various areas of the lagoons were colonized, including the present site of Torcello, before the seat of administration was fixed at a group of islands known as Rivus Altus (“the highest bank”), later the Rialto, the present location of the city of Venice. The official Ab Urbe Condita is March 25, 721 A.D. Paoluccio Anafesto, the first ruler of the lagoon communities, called the doge (the Venetian equivalent of Latin dux or Florentine duca/duce, meaning leader or duke), is said to have been elected in the year 697.

The most significant fact of this entire period is that the whelp of what was later to become Venice survived and grew thanks to its close alliance with the evil Emperor Justinian in Constantinople, an alliance that was underlined in later years by intermarriage of doge and other leading Venetian oligarchs with the nobility of Byzantium, where a faction embodying the sinister traditions of the Roman Senate lived on for a thousand years after the fall of Rome in 476.

Venetian families are divided into two categories. First come the oldest families, or Longhi, who can claim to prove their nobility substantially before the year 1000. The Longhi include many names that are sadly familiar to the student of European history: Dandolo, Michiel, Morosini, Contarini, Giustinian (perhaps related to the just- mentioned Byzantine emperor), Zeno, Corner (or Cornaro), Gradenigo, Tiepolo, and Falier. These old families held a monopoly of the dogeship until 1382, at which time they were forced to admit the parvenu newcomers, or Curti, to the highest honor of the state. After this time new families like Mocenigo, Foscari, Malipiero, Vendramin, Loredano, Gritti, Dona, and Trevisan came into the ascendancy."

"between 180 and 280 AD, the empire collapsed. It was reorganized by Aurelian, Diocletian, and Constantine with a series of measures that centered on banning any change in the technology of the means of production, and very heavy taxation. The Diocletian program led to the depopulation of the cities, serfdom for farmers, and the collapse of civilization into a prolonged Dark Age.

The Roman Empire in the West finally collapsed in 476 AD. But the Roman Empire in the East, sometimes called the Byzantine Empire, continued for almost a thousand years, until 1453. And if the Ottoman Empire is considered as the Ottoman dynasty of an ongoing Byzantine Empire, then the Byzantine Empire kept going until shortly after World War I. With certain exceptions, the ruling dynasties of Byzantium continued the oligarchical policy of Diocletian and Constantine.

Venice, the city built on islands in the lagoons and marshes of the northern Adriatic Sea, is supposed to have been founded by refugees from the Italian mainland who were fleeing from Attila the Hun in 452 AD. Early on, Venice became the location of a Benedictine monastery on the island of St. George Major. St. George is not a Christian saint, but rather a disguise for Apollo, Perseus, and Marduk, idols of the oligarchy. Around 700 AD, the Venetians claim to have elected their first doge, or duke. This post was not hereditary, but was controlled by an election in which only the nobility could take part. For this reason, Venice erroneously called itself a republic.

In the years around 800 AD, Charlemagne, King of the Franks, using the ideas of St. Augustine, attempted to revive civilization from the Dark Ages. Venice was the enemy of Charlemagne. Charlemagne’s son, King Pepin of Italy, tried unsuccessfully to conquer the Venetian lagoon. Charlemagne was forced to recognize Venice as a part of the eastern or Byzantine Empire, under the protection of the Emperor Nicephorus. Venice was never a part of western civilization.

Over the next four centuries, Venice developed as a second capital of the Byzantine Empire through marriage alliances with certain Byzantine dynasties and conflicts with the Holy Roman Empire based in Germany. The Venetian economy grew through usury and slavery. By 1082, the Venetians had tax-free trading rights in the entire Byzantine Empire. The Venetians were one of the main factors behind the Crusades against the Muslim power in the eastern Mediterranean."