
Flag of the Republic of Venice. The Lion of Saint Mark was the official symbol. Saint Mark was an evangelist of early Christianity who lived in Alexandria in Egypt during the 1st century AD. His remains were stolen in 828 AD during a Venetian campaign in Alexandria, and placed in St Mark's Basilique in Venice. Ever since St Mark (San Marco) has been the patron saint of Venice.
History
Origins of Venice
The Venetian Lagoon served as a shelter for Roman citizens during the collapse of the Western Roman Empire in the 5th centuty AD. Invading Avars, Huns and Slavs were often repelled. The founding of the Republic of Venice is attributed to have happened in 697, but no accurate accounts exist of that time. In the 8th century, the Byzantine Empire took control of parts of the Italian peninsula, including the Venetian Lagoon area.
In the 9th century the island of Rialto was settled and became the capital of the republic, which was nominally part of the Byzantine Empire but effectively ruled by a local Doge, a name derived from Latin Dux and equal to English Duke. Venice started flourishing through the establishment of maritime trade routes with the Levant and the Byzantine Empire. Around 1000 AD areas of the Dalmatian coast (now Croatia) were added to the republic's territory in order to establish fortifications along the naval routes.

Venice in 1000 AD.
Rise of a naval power and the Crusades
Venice developed a formidable fleet and was involved in many wars, including the crusades when it was initially serving to protect the Byzantine Empire from Arabs and Turks. The Venetian minority in Constantinople enjoyed a large degree of prosperity which resulted in a large anti-Latin massacre in the Byzantine capital in 1182. To return the 'favour', Venice turned the Fourth Crusade (1202-4) against the Byzantine Empire which led to the infamous Sack of Constantinople and the breakup of the Byzantine Empire. The empire would never be able to fully recover again, despite its restoration in 1264. Many stolen artefacts from Constantinople can still be seen in Venice today.
Stato del Mar
The Fourth Crusade saw huge territorial expansion for the Republic of Venice, adding the Ionian Islands, Euboia and Crete to its territories. The Venetian overseas territories were named Stato del Mar. Cyprus was gained in 1489 but lost to the Ottomans in 1570.

Expansion of Venice from the Fourth Crusade (1202-4) until the Great Turkish War (1684-99).
Venetian-Ottoman Wars
The Ottoman Empire expanded rapidly into the Balkans in 14th and 15th centuries, leading to many naval wars with Venice over control of the Eastern Mediterranean. Cyprus was lost after the Battle of Lepanto in 1570. Crete was lost in 1669. Venice occupied the Peloponnesos (the Morea) during the Great Turkish War of 1684-1699, but had to retreat from the area after. Dalmatia and the Ionian Islands remained under Venetian control.
Decline of the Republic of Venice
The Great Explorations of the 15th and 16th centuries decreased the relevance of the Mediterranean trade routes with the orient, slowly reducing the economic and military power of Venice. Western Europeans powers such as France and Austria increased their grip on the region. In the 18th century it became apparent that the Republic of Venice was not able to defend itself anymore. In 1797 the Treaty of Campo Formio partititioned the Republic of Venice between France and Austria.
Foreign domination (1797-1866)
Venetia became an Austrian crown land in 1797, with Dalmatia awarded to France. In 1805 France annexed Veneto after the Battle of Austerlitz and merged it with the Italian Republic to form the Kingdom of Italy. In 1815 both Veneto and Lombardy were returned to Austria after the Congress of Vienna.

The Kingdom of Lombardy-Venetia as part of Austria from 1815 until 1859.

Flag of Lombardy-Venetia. The Austrian eagle is featured but no reference to San Marco.
The Kingdom of Lombardy-Venetia was an Austrian crown land from 1815 until 1866. Attempts to break from Austrian rule were undertaken in 1848 during the First War of Italian Independence, but the Austrians were able to regain control the next year. During the Second War of Italian Independence (1859-1861) Lombardy was ceded to the Kingdom of Sardinia, which was in the process of forming a unified Italy. Venetia followed in 1866 after the Austro-Prussian War which saw Austria severely weakened. It was formally ceded to France and two days later passed to Italy.
Currency
The primary unit of account of Venice was the Lira of 20 Soldi or 240 Denari. Over the centuries these units were debased gradually and new coins were introduced.
Grosso
The Grosso was a silver coin worth 26 Denari introduced during the reign of Enrico Dandolo (1196-1205). It had a high purity (.965) and weighed a bit more than 2 Grams. The Grosso's design was inspired from the Byzantine silver Aspron Trachy. The Venetian Grosso was frequently used in European trade and copied elsewhere. The German Groschen, Polish Grosz and English and Flemish Groat are all based on the Grosso.
The Grosso was initially worth 26 Denari. It was revalued to 28 Denari in 1270 and 32 Denari in 1282. It was worth 4 Soldi or 48 Denari from 1350. The last Grosso in its pure form was minted in 1354, but debased versions continued until the introduction of the silver Lira in 1471.
Gold Ducat or Zecchino
The most influential Venetian coin was the gold Ducat of .986 fineness and a weight of 3.43 grams, introduced in 1282. The gold Ducat became a standard for trade coinage for many European countries. It was initially worth 48 Soldi or 18 Grossi but its value versus account money increased over time:
1282: 48 Soldi or 2.4 Lire
1328: 64 Soldi or 3.2 Lire
1379: 77 Soldi or 3.85 Lire
1382: 3 Lire 19 Soldi 6 Piccoli (3.975)
1399: 93 Soldi or 4.65 Lire
1408: 96 Soldi or 4.8 Lire
1417: 100 Soldi or 5 Lire
1429: 104 Soldi or 5.2 Lire
1443: 114 Soldi or 5.7 Lire
1472: 124 Soldi or 6.2 Lire
In 1472 the Ducato became a unit of account fixed to 124 Soldi. But the price of gold continued to rise which caused the actual gold minted ducats to increase further in value. To distinguish the gold ducats from 'paper gold ducats', the coins were named Zecchino from the Italian word Zecca which means mint. In the 17th century, silver Ducats worth 124 Soldi were introduced next to gold Zecchini which traded at (much) higher value. The gold coins were valued at:
1519: 136 Soldi or 6.8 Lire
1525: 150 Soldi or 7.5 Lire
1545: 157 Soldi or 7.85 Lire
1568: 160 Soldi or 8 Lire
1570: 172 Soldi or 8.6 Lire
1579: 9 Lire
1588: 10 Lire
1687: 17 Lire
1739: 22 Lire
Silver coinage
In 1471 a silver coin of 6.52 grams of .948 silver known as Lira Tron was introduced. It was named after the doge that ordered its mintage: Nicoló Tron. It was the first silver Lira in the whole of Italy, and replaced the Grosso as primary silver coin in Venice.
The next doge Nicoló Marcello introduced a coin of half Lira or 10 Soldi, and continued to be named Marcello even long after his reign. Marcello's successor Pietro Mocenigo had new Lira coins minted, and these were named Mocenigo. Mocenigi and Marcelli continued to be minted under subsequent doges, and were even revalued to 21 and 10.5 Soldi in 1518 and to 24 and to 12 Soldi in 1523.
Denari, Piccoli and Bagattini
The Bagattino was an alternative name for a Denaro. Six Bagattini was a Sesino, or half Soldo.
Quartarolo and Bianco
Subdivisions of the Denaro were the Bianco (1/2) and the Quartarolo (1/4). The value of the Quartarolo is however debated, as between 1260 and 1320 both 2 Quartaroli and Bianco coins were minted which seems redundant as they would be worth the same. Different theories exist. One states the Quartarolo was linked to Denaro and the Bianco to Grosso causing the values to diverge. Others state that Quartaroli were only used in Greece as the Venetian version of the Byzantine Tetarteron. And another theory claims that a Quartarolo was worth 1/4 Bianco or 1/8 Denaro.
Tallero
The Tallero was based on the Austrian Thaler (28 grams of .835 silver) and mostly used for trade with the Levant. It was valued at 10 Lire at the end of the 18th century.
After 1797
The Venetian Lira remained in circulation during the first Austrian era of 1797 until 1805, with coins depicting the Austrian eagle and emperor. It was replaced by the Lira of the (Napoleonic) Kingdom of Italy in 1807.
Lombardy-Venetia
The Austrians introduced a Lombardy-Venetian Lira in 1822, worth 1/3rd of an Austrian Florin. The Scudo was equal to the Conventionsthaler and worth 6 Lire. The Lira was decimalised into 100 Centesimi.
In 1862 the Lira was replaced by the Florin at a rate of 3 Lire per Florin. One Florin equalled 100 Soldi. In 1866 the Florin was replaced by the Italian Lira at a rate of 2.469 Lire per Venetian Florin.
Republic of Venice (pre-1797)
https://en.numista.com/catalogue/italie_etats-49.html#devise896
Lombardy-Venetia (1815-1866)
https://en.numista.com/catalogue/italie_etats-8.html#devise382
Lombardy-Venetia Florin (1862-1866):
https://en.numista.com/catalogue/italie_etats-10.html#devise1034
Provisional Government of Venetia (1848-9):
https://en.numista.com/catalogue/italie_etats-52.html#devise1035
Kingdom of Candia (Venetian Crete, 1205-1669):
https://en.numista.com/catalogue/italie_etats-53.html#devise2351