As the Venetians grew in economic and trade power, the declining Byzantine Empire in the late 11th century further sought maritime and financial help.
In 1092, Alexios I of the Comnenus dynasty issued the Edict of the Golden Seal, which stipulated that Venice could import and export goods duty-free in all cities of the empire, except for a few ports in Crete, Cyprus and a few ports on the Black Sea coast, and also took over the Amalfi inns and other facilities of the empire.
At the same time, Venice also gained the right to establish a commercial area in Constantinople, impose some customs duties, and free access to important seaports of the Byzantine Empire, such as Corinth.
After the 11th century, out of diplomatic necessity, Byzantium also granted the Venetians and Genoese the privilege of imposing import and export tariffs, paving the way for the development of the Italian city republic, but eventually caused the paralysis of Byzantine state commerce and the total collapse of state finances.
The slow and continuing decline of Constantinople brought new opportunities to the Italian city-states, and by the 11th and 12th centuries, Constantinople had gradually lost control of the eastern Mediterranean, giving Italian cities greater opportunities to control trade routes to the east.
By the 11th century, Italy's trade was more extensive than elsewhere in Europe except Arab-controlled southern Spain.
The salt production in the Adriatic lagoon region, along the Tuscan coast and at the mouth of the Tiber River is particularly large, and it is one of the sources of Venice's wealth.
Due to the lack of agricultural areas in Venice, it had to go on trade routes in the first place. It took advantage of its close political ties with Byzantium to import oriental art and fabrics, which it exchanged for grain and other goods.
Many southern Italian towns also prospered through trade with the Levant. By the 11th century, Salerno developed into a great cultural center, with a prestigious medical school.
The merchants of Genoa, Pisa and Venice acquired important commercial rights in the East, which became the backbone of prosperity in the following centuries.
Spices shipped from the Levant (both edible and medicinal) were extremely profitable: a boatload of pepper, cinnamon, ginger, saffron, cloves or nutmeg was worth a fortune to the Western European market.
Venice alone imported pepper in some years traded more than a million pounds of silver.
In addition, with Constantinople as the hub, the Byzantine Empire also maintained commercial exchanges with the interior of Europe, and goods from the East departed from Constantinople, reached Marseille through the Mediterranean, and then transported by land to the French mainland; Timber, wheat, wool, wine, olive oil, etc. were transported along this trade route from the interior of Europe to Byzantium.
Although such commercial links were not always available, they provided a port of foreign exchange for the European interior, which was then in decline in commerce.
Since the Sui and Tang Dynasties, Constantinople's economic, trade and cultural exchanges with China have been unified, and control over the Western Regions has been strengthened, and the development of the Silk Road has ushered in another peak.
Chinese texts refer to the Byzantine Empire as the "State of Whisk" because the Greeks referred to Constantinople as Stinpolin, Stanbulin, Polin, or Bulin. Often referred to as He Polis (city) or Ten Polin (to the city) in spoken and written language; "Ling" is actually Polin's voice.
At the beginning of the 7th century, Pei Cheng adhered to the will of the Sui Emperor to manage the Western Regions, and induced the merchants of the Western Regions who came to Zhangye to do business, described the geography of his country's mountains and rivers and the routes of access, and wrote the "Records of the Western Regions" in three volumes, saying: "From Dunhuang, as for the West Sea, all three paths, each with its own belt."
The northern road runs from Yiwu, through Pu Zhuhai, Tiele Bu, and the Turkic Khan's Court, through the Beiliu River, to the country of Fuling, and reaches the West Sea. The road runs from Gaochang, Yanqi, Guizi, Shule, and Duluoling, and then passes through the Cymbal Khan, Su to Shana, Kang, Cao, He, Xiao'an, Mu, to Persia, and reaches the West Sea.
Its southern road runs from Shanshan, Khotan, Zhujubo, Jiugantuo, Duluoling, and then through Humi, Tocharian, Ruyi, Taiyan, Caoguo, to Northern Brahmins, and reaches the West Sea. Its three countries also have their own roads, north-south traffic... Therefore, it is known as Yiwu, Gaochang, Shanshan, and the gateway to the Western Regions. Dunhuang is its throat. ”
The Old Book of Tang records that Constantinople "had its hall with shivering as the pillar, gold as the ground, ivory as the door, and incense wood as the pillar." It has no tiles, pounding white stone for the end, and on the Luo Zhitu roof, its dense and shiny, and like jade. As for the festival of summer, people are tired of the heat, but they divert the water undercurrent, and they go up all over the house, and the mechanism is ingenious, and no one knows it. The viewer only hears the sound of the spring on the house, and the four eaves of Russia flying, the hanging waves are like a waterfall, and the air is stirred into a cool breeze, which is ingenious. ”
With Tang I, there was also a prominent feature in the cultural ties between China and the Byzantine Empire, namely the spread of Nestorianism.
Nestorianism, or Christianity, advocated Christ's "theory of the two natures of God and man", which split from the Orthodox Church.
In the ninth year of Tang Zhenguan (635), Nestorian bishop Aro Ben went to Chang'an, received courtesy from Emperor Taizong of Tang, allowed him to preach, and built a temple for him, and since then, Nestorianism has taken root in China.
During the reign of Emperor Gaozong, the Jingji Temple was divided within the prefectures, with Aroben as the great king of the town state, "The temple is full of hundreds of cities, and the family Yin Jingfu." "When Nestorianism first entered, everyone in the Tang Dynasty thought that Nestorianism came from Persia, and they all called Nestorianism a Persian temple.
In 745, Emperor Xuanzong of Tang issued an edict in response to this, changing the Liangjing Persian Temple to the Daqin Temple, and the Daqin Temple established by various prefectures and counties in the country was also renamed.
The "Nestorian Popular Chinese Stele of Tang Daqin", completed in 781, reflects the grandeur of the spread of Nestorianism in China at that time, and shows the success of Nestorian activities.
However, with the destruction of Buddhism by Emperor Wuzong of Tang in 845, Nestorian religion was also implicated and fell into a desperate situation, and by the late Tang Dynasty Fifth Dynasty had completely ceased to exist. Some of the Nestorians, who could not gain a foothold in the Central Plains, may have abandoned their faith and some moved to the periphery controlled by the government.
In 879, after the Huangchao rebels conquered Guangzhou, they slaughtered 120,000 to 200,000 Muslims, Jews, Christians and Zoroastrians.
These Christians may include Nestorian and their descendants who were forced to leave because their movement in the Central Plains was restricted.
In 980, the archbishop sent six Christian priests to China to rectify the church, only to find that Christianity in the Central Plains had become extinct and return to Baghdad.
The Nestorian had the medical knowledge and medical technology of the Byzantine Empire, and its Chinese missionary process had the characteristics of medical assistants, and the "Great Qin Nestorian Popular Chinese Stele" recorded that the Nestorian engaged in related medical activities, "the sick came to rise", in order to win believers.
In the winter of 740, Emperor Xuanzong's eldest brother Li Xian the Prince of Ning was seriously ill and could not be cured for a long time, and the Nestorian Chongyi recovered after treatment, for which Emperor Xuanzong specially gave Chongyi a crimson robe and a silver fish bag to show his grace.
Byzantine medical and medical knowledge was also spread along with the medical activities of the Nestorians, as recorded by Sun Simiao in his "Thousand Golden Fangs".
In the seventh year of the Xingguo of the Northern Song Dynasty (982), Wang Yande visited Gaochang Uighur, and saw that "there are Mani Monastery and Persian monks, each holding its own teachings, and the so-called outsiders of the Buddhist scriptures." ”
Taiping Xingguo "On May 3, 9th year, the Uighurs of Xizhou and the Persian foreign provinces came to pay tribute" ("Song Shi Tianzhu Biography"). Wang Yande's so-called "Persian monks" and "Persian foreign paths" both refer to Gaochang Jingjian.
The style of the Gaochang Christian murals also has a distinctly Byzantine art style, including a depiction of a group of believers holding branches hugging a priest, depicting Palm Sunday, the Sunday before Easter when Christ is welcomed into Jerusalem.
In addition to written records, many Byzantine gold coins were also unearthed in the country, testifying to the direct trade between the two countries at that time.
The Sui Book of Food and Goods mentions that at the beginning of the Northern Zhou Dynasty (557-580), "the counties of Hexi may use gold and silver money, and the officials cannot help it." "The money used in the Western Regions is Byzantine gold coins, and the silver coins are Persian Sassanid silver coins.
About 40 Roman (Byzantine) gold coins and their imitations have been found in China, of which more than 20 have been examined in the imperial era, and their excavations are wide-ranging, found in Xinjiang, Ningxia, Gansu, Shaanxi, Inner Mongolia, Hebei, Henan, Liaoning, Zhejiang and other places, most of which are necessary places for Silk Road trade.
In addition, the Blood Wei No. 1 Tomb in Dulan County, Haixi Mongol-Tibetan Autonomous Prefecture, Qinghai, is an early Tang Dynasty Tubo tomb, in which Byzantine brocade and large food brocade produced in the Arab world were also found, reflecting the grandeur of international trade in the Tang Dynasty.
There is not much in the Official Book about olive oil and wine. Olive oil is sold in grocery stores throughout the city, there are no specific regulations on processing or importation, and at the end of the 9th century, the price of olive oil in Constantinople was 1 copper coin Obol per liter.
Research by John Hayes on ceramics found in Sarahan suggests that after late antiquity, it was possible to carry oil or wine into the city with amphorae.
There is no mention of the early olive oil depots near Stragion in the Official Book, nor elsewhere in the period. The wine is sold by the innkeeper (kapeloi) and is sold in a fixed volume of 30 or 3 liters, in addition to being sold by the glass.
Like vendors selling wax and soap, grocery stores sell goods scaled on scales. The Official Book lists these weighed goods as meat (but different from meat sold by butchers), salted fish (not fresh), meals, cheese, honey, vegetables and butter, and olive oil.
In addition to food, grocers sell resin, cedar and flaxseed oil, camphor, plaster, pottery, and nails. They are not allowed to sell items weighed in a balance, which can only be sold by myrepsoi.
The latter products include raw materials for fragrances and perfumes, pharmaceuticals and raw materials for dyeing. The Official Book does not mention the pharmacists themselves. Grocery stores, inns and bakeries are scattered throughout the city, while Maipsoy has only one between Milion and Chalke.
As trade expanded further, other Italian cities competed with Venice, and Florence launched a comprehensive challenge to Venice in areas such as finance and textile trade; The Genoese competed with them for commercial dominance in the Mediterranean.
Smaller cities such as Prato focus on mastering the specialized handicraft sector. In 1016, the Pisans and Genoese united to expel the Arabs from Sardinia, and the two sides fought fiercely for commercial and political strife.
In 1100, Venice defeated the pirates of the Dalmatian belt and established its supremacy over the Adriatic Sea. In 1135, Amalfi was ruined by the invasion of Pisa and never fully recovered.
Due to the hostile relationship between the Normans and the Eastern Roman Empire, trade routes to the Levant were blocked, which was very beneficial to the northern cities, especially Venice; And under the Norman monarchy, the town merchant class was heavily taxed, and trade in the south weakened further.
In the long run, the southern ports could not compete with those in the north in any way: they were too dependent on the role of trade centers and lacked vibrant agricultural areas, which was one of the key factors for the prosperity of northern towns.
Even in Puglia, the wealthiest region in the south, wheat and oil production available for sale was limited in the 11th century. Competition among commercial cities has energized business activity in the Eastern Mediterranean region and allowed the cities themselves to develop rapidly.
In the 12th and 13th centuries, these cities expanded rapidly, and the population of Florence increased from a few thousand in 1000 AD to about 100,000 in the early 14th century, making Florence one of the five largest European cities along with Venice, Milan, Genoa and Paris.