The immense commercial trade, wealth, and sea power of the Republic of Venice was rooted in the ships built in the industrial site known as the Arsenale, or arsenal. It was first established in 1104 and continued building warships, merchant ships, armor, crossbows, catapults, weapons, and artillery for eight centuries.

The 24-hectare (60-acre) site spans water and land on the eastern end of the city and is surrounded by 15-meter (50 ft) tall defensive walls enclosing drydocks, wet docks, forges, and workshops. From its foundation, it was a government-controlled factory designed to produce ships and weapons to defend the Republic of Venice's trade and to exert its dominance throughout the Mediterranean. Venice's immense wealth came from trade as far as Egypt and Syria, and its connection to the Silk Road. Venetian ships carried trade to Egypt and transported pilgrims to the Holy Land.

The Arsenale's entry gate features two distinctive towers, which appear in historical images of Venice and look the same today. Visitors to its front gate are still confronted by a row of massive marble lions standing guard, which were brought back from Greece to Venice as prizes of war.

Behind its brick walls were workshops and docks where everything needed to maintain a maritime force was standardized and stored on-site. All materials were produced there: nails, pitch, caulk, rope, rigging, sails, oars, keels, decks, and masts, along with weapons including armor, swords, lances, gunpowder, pistols, mortars, and artillery.

Much like an assembly line, their ships were constructed in a system where the keels were laid, then the hulls were floated from one work shed to another, as the ship progressed towards completion. Artisans and masters continually improved the technology and were rewarded for their innovations.

Every workday morning a bell tolled in the eastern end of Venice, known as Castello, which summoned the workers, called Arsenalotti, to work. They had only a short walk to the gates from their apartments, and the most skilled were often given special housing. These workers included men, who worked as carpenters, riggers, blacksmiths, forgers, and rope makers, and women, who worked spinning thread, weaving sailcloth and silk banners on looms, sewing sails, and other tasks. Some women were allowed to apprentice to their fathers in traditionally male tasks.

Arsenalotti received good benefits: they were provided with good wages, could earn promotion to become foremen or masters, and wine was brought in each day to sustain them. Every Saturday was payday, and workers received their cash payments at the front gate. Although many Venetian sources portray the workers as satisfied, there were occasional protests, and in 1569, a cutback in hours led to a riot. Workers organized among themselves into guilds based on their specific trade (shipwrights, sawyers, caulkers, ironsmiths, gunsmiths, etc.) and established funds to support those who might be injured or even killed at work. But the most valued benefit was to sign on their children as apprentices and move them up to become their successors.

In time of war, the Arsenalotti could be drafted to serve on warships. Caulkers, who possessed critical skills, were regularly posted on ships to conduct emergency repairs. Workers expected to be assigned to ships at some point in their careers, sometimes for years, and might view rowing a galley as a means of surviving hard times. If a worker was convicted of a crime, they might be sentenced to row on the galleys or to work for a number of years in the shipyard at half pay.

Poet Dante Alighieri's Canto XXI recalled watching the workmen boiling pitch into black tar to be used in the waterproofing of ships. Dante described watching the boiling cauldrons as resembling a hellish atmosphere. The workers then set to pressing the pitch onto the hulls of the ships.

The proti or masters, who managed each step of the production process, held the highest respect, rank, and pay and might number as many as a thousand. If needed, the workforce might expand to several thousand and then rapidly shrink with less demand. Masters managed teams of skilled craftsmen and apprentices who learned the finer points of a specific trade. Many worked all their lives in a single area of expertise, and a veteran who continued to work into his sixties or seventies was not considered unusual.

These workers had long held a special place in Venetian society, which historian Robert C. Davis termed "a civic role," meaning they were honored participants in public events (Davis, 150). During times of religious rites or celebrations, the Doge and his entourage took to their elaborate ceremonial barge, known as the Bucintoro, out into the lagoon. The oared galley was painted bright red and elaborately decorated with gold leaf. It was rowed by teams of the Arsenale's workers, who brought the Doge to the center of the lagoon, where he threw a golden ring into the sea as thanks for another year of prosperity. When a new Doge was elected, the workers carried him through the city, and they rowed his barge during the ceremony known as the Sensa (Marriage to the Sea).

The workers also had regular responsibilities in the protection of the shipyard. They served as security guards patrolling the shipyard at night and as firefighters in an emergency. In 1508, a massive explosion in the gunpowder workshop killed many workers and destroyed part of the Arsenale.

Venetian historian Marin Sanudo was especially impressed by the Arsenale's forges, where blacksmiths constructed massive siege weapons: "There are enormous bombards and catapults of inestimable force, which no city or castle would be strong enough to withstand…" (Sanudo, 18 to 19).

Nearby was the most important covered work area, the Tana, or ropewalk, built in 1579. The Tana had three long aisles and was 316 meters (1,036 ft) long or longer than three football fields. This was where workers reeled hemp fibers into strands and then twisted the strands into rope to be used for rigging ships and mooring hawsers. The massive roof was supported by 84 brick and stone columns, each over a meter in diameter. The government of the Republic appointed overseers or Signori (Lords) to control the price and assure the quality of supplies. When speculators attempted to monopolize the hemp market, which was used by the ton, the state broke the monopoly. Then they instituted a grading system, which tested and labeled the quality of rope. Historian Frederic C. Lane noted that the fate of a Venetian ship and its crew on the open sea depended entirely upon the quality of the rope used in rigging and mooring. The Arsenale assured its captains that they had the best rope.

Behind the ropewalk were acres of dockyards where a ship's keel could be laid. Beech trees were selected for oars, and pines were harvested to be burned for pitch. In the government-controlled forests, Venetian officials marked trees ideal for masts and even tied young trees into curved shapes to be later harvested for keel beams. Skilled sawyers cut the trees and then floated them down the rivers into the delta of Venice. In the dockyards, massive wooden ribs were carved by skilled carpenters, attached to the keel, then decking and masts were raised. After each step, the nascent ship was floated to another covered shed where a new set of artisans took to their tasks. The process operated like an assembly line and involved the prefabrication of subparts for ships, which were then put in storage. If war threatened, then the Commander of the Arsenale would order workers to prefabricate these parts and store them in warehouses. Then, when needed, they could be rapidly assembled into completed warships.

In 1574, King Henry III of France visited the Republic of Venice, and the Doge hosted him for a full day on the site. The king was led from one area to another to watch every step in the construction of a warship. The Venetians' aim was to impress upon him that they could replace any ship lost in battle in a short time, using this system of prefabricated parts.

These methods were on a large scale and so innovative that they predated modern industrial organization by centuries. Economic historian Frederic C. Lane termed the 16th-century Arsenale "as perhaps the largest industrial plant of that time" (Lane, 1992, 146). Scholar Robert C. Davis quoted Zuane Bernardo in 1676, referring to it as "the Factory of Marvels" (Davis, 3).

When their navy had problems with the operation of oars on a new galley, they invited Galileo Galilei, a professor at the University of Padova, to offer suggestions. A series of visits and then letters were exchanged between Galileo and the head of the arsenal, Giacomo Contarini, between 1592 and 1593. Later in life, Galileo, in his Discorsi, wrote about the influence on his thinking after observing the Arsenale's methods of ship construction. Leonardo Da Vinci was also invited as a consultant, but he left no record of what they discussed. Nevertheless, the Arsenale had manufactured catapults for siege warfare, and Da Vinci later drew images of arsenal workers as well as designs for catapults.

Venice regarded the Arsenale as its key defense against enemy attack and the source of protection for its trading empire. The rivals they feared most were the Ottomans, whom they called "Il Turco" (The Turk). In 1570, Venice joined the Holy League of France, Spain, and the Vatican to challenge the Ottoman Empire in the Battle of Lepanto. Over half the Holy League's fleet came from the arsenal shipyards, including innovative ships of war with multiple turret-mounted bronze cannons. The innovative design, which allowed a ship to simultaneously fire in multiple directions, gave the Holy League a distinct advantage in sea battles.

Because there was no land to cultivate within Venice, it was not a feudal state. Without land for agriculture, wealth had to be earned from commerce, and food had to be imported from the mainland. In the 15th century, the Republic of Venice solidified its control over northeast Italy as its population grew to a quarter of a million. In times of peace, Venice dominated trade along the Adriatic coast and into the eastern Mediterranean, and especially with Egypt. Ships capable of carrying 250 tons of spices and other valuable goods brought Venice tremendous profit. An innovative method of financing these commercial enterprises was a contract between the ship's captain and investors, as the colleganza. This gave a ship captain the financial power to have a ship built, hire a crew, and acquire goods that could reap great profit, both for the captain and the investors. Venice's Murano glass was often used as an international currency to power the trade in exotic spices and Egyptian cotton. Commercial power built the Venetian city-state into a center of wealth.

In 1797, after the Republic of Venice was invaded by Napoleon Bonaparte's troops, the city was looted. The occupiers hoisted the four-horse statue off the roof of the Saint Mark's Basilica, took paintings and other valuables, which were shipped off to Paris. The Bucintoro was set on fire and its gold leaf scavenged. The city of Venice never had defensive walls around the city, but the Arsenale was protected behind high, thick brick walls.

After Napoleonic France ceded Venice to the Austrians, they occupied the city and took control of the shipyard from 1814 to 1848. When the Austrian occupation ended, the shipyard was left moribund. Workers had been released, and the advent of steel-hulled warships destroyed its importance. Venice later became part of the Kingdom of Italy, and in 1883, the Italian Navy brought the facility back into use as a shipyard. Work began with the installation of a massive Armstrong-Mitchell hydraulic crane for modern steel ship construction. In 1895, the nearby Public Gardens were opened to host the international Biennale Art exhibition.

In April of 1915, Italy joined the Allies and fought in the First World War (1914 to 18). Only a month later, Austrian forces invaded the lagoon by ship and by air and attacked the Arsenale with bombs and incendiaries. On the nights of May 24 and 25, the wooden roofs of its sheds burned, and the crane was damaged.

Since 1964, one building has been home to the Museo Storico Navale (Naval History Museum of Venice), which displays a full-scale replica of the Bucintoro that is still used for ceremonies today. The Italian Navy has a command center for its Adriatic fleet at the Arsenale offices. The city of Venice has plans for adaptive reuse of the Arsenale as an exhibition space, and in spring 2025, it hosted the Biennale of Architecture in the Tana ropewalk and opened the dockyard area to the public.