Hospitaller Warfare: Castles, Soldiers and Fleets

The Knights Hospitaller began as a religious community caring for sick and poor pilgrims in Jerusalem. In the 12th century, they also took on armed duties, helping defend pilgrims and the Christian states of the eastern Mediterranean. Their warfare depended on more than professed knights: garrisons included other brothers and hired troops, while European estates supplied income and personnel. Over time, the Order’s military centre shifted from castles in the Levant to an island fleet based first at Rhodes and then Malta. This account follows that change from the Order’s 12th-century militarization to the loss of Malta in 1798.

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From hospital to armed order

Pope Paschal II formally recognized the Order in 1113. Its armed role grew during the following decades, as the Hospitallers took responsibility for protecting pilgrims and defending territory. Raymond du Puy, master from around 1120, is associated with organizing the military side of the Order. This did not replace its charitable work: the brothers continued to run hospitals, but the institution also acquired the people, property and authority needed to wage war.

The Order was a religious community as well as a military organization. Its members included priest brothers, knight brothers and sergeant brothers. Knights and sergeants served as combatants, though their status and obligations differed. The Order also employed secular soldiers who were not professed members. In the Holy Land, local auxiliary troops known as turcopoles provided light cavalry; the officer responsible for them was called the turcopolier. The combination mattered because the number of religious brothers alone could not provide every soldier required for a campaign or a network of garrisons.

Command, recruitment and resources

The grand master led the Order, while senior officers divided responsibility for its administration and military needs. The marshal prepared the Order for war, including the procurement of weapons, armour, horses and artillery. Other officers managed provisions, finances and the central hospital. From the 13th century, the turcopolier oversaw local auxiliary forces, and an admiral directed the fleet. The precise organization changed over time, but warfare depended on coordinating these offices rather than on a single battlefield commander alone.

The Order drew much of its income from properties in Europe. These were grouped into priories and smaller administrative estates called commanderies. A commandery was managed locally and sent a share of its revenues to support the Order’s central activities. Those funds helped pay for garrisons, ships, hospitals and supplies. Revenue did not always arrive reliably, however, and military commitments could exceed what the Order’s estates or its supporters could provide.

Recruitment also relied on the Order’s European connections. Brothers came from different regions and were organized into groups known as langues, or “tongues”, which reflected their origins and languages. These groups had administrative responsibilities and, in later periods, particular offices were associated with them. The system connected the Order’s island headquarters to its European membership and resources, but it could not guarantee that enough trained people or money would be available when needed.

Castles and garrisons in the Levant

In the crusader states, Hospitaller castles helped defend territory and routes used by pilgrims and armies. Rulers and nobles sometimes entrusted strongholds to the Order because it could maintain a permanent military presence. The Hospitallers also acquired and repaired fortifications themselves. Bethgibelin, granted to them in 1136, helped protect the southern frontier of the Kingdom of Jerusalem and roads linking Ascalon and Hebron. In 1142, the Order received Krak des Chevaliers in Syria. By about 1180, one estimate counted 25 castles under Hospitaller control.

A castle was useful only if it could be supplied and held. Garrisons required soldiers, equipment and provisions, while the Order’s wider network helped finance and reinforce its positions. Brothers-at-arms served alongside sergeants and hired fighters, with local auxiliaries available for some duties. The Order’s castles were therefore part of a broader military system: its European revenues supported forces in the eastern Mediterranean, and those forces defended both the Order’s own holdings and territories entrusted to it.

The loss of Acre in 1291 ended the Order’s role in defending the remaining crusader strongholds in the Levant. The Hospitallers withdrew to Cyprus, where they lacked an independent territorial base. They then took Rhodes, establishing control of the island in 1310. This relocation altered the balance of their military activity. Fortifications remained essential, but defending an island and maintaining links across the sea made ships a continuing requirement.

Ships, crews and command

Hospitaller ships initially carried pilgrims, merchants, goods and troops as well as supporting military operations. By the mid-12th century, the Order had acquired transport ships, and it later built vessels at Acre. After the fall of Acre, Pope Nicholas IV urged the military orders to develop fleets. In 1291, he directed that half of the Hospitallers’ European income be used to build a fleet, and in 1292 he authorized its galleys to defend the Armenian Kingdom of Cilicia. A reference to a Hospitaller admiral survives from 1299.

The Order’s ships needed sailors as well as armed men. Crews were recruited in port towns, and experienced soldiers could also be hired. A galley required a large fighting complement in addition to its crew, so finding enough people to man ships could constrain operations. On Rhodes, naval service, sometimes called a caravan, helped connect the knights’ obligations to the fleet. But ships competed with garrisons and other duties for personnel and money. The Order might charter or buy vessels, build them, or receive ships from outside supporters.

The Italian langue held the admiral’s office in the Order’s later medieval organization. The admiral supervised ships and their crews, while a fleet commander could direct vessels at sea. At Rhodes, naval responsibilities were linked to the broader military command, including the marshal. These arrangements gave the Order a way to organize maritime forces, but they did not remove its reliance on outside funding, recruitment or cooperation with other Christian powers.

Rhodes and the island defence system

On Rhodes, ships were needed to defend the island, patrol nearby waters and support operations elsewhere in the Aegean. Galleys formed the core of the fleet for much of the period. The Order also maintained smaller craft and, from the late 15th century, larger sailing ships. Typically, the Rhodian fleet had only a few galleys at its disposal, though it could assemble more for particular needs. Such limits reflected both finance and the challenge of recruiting enough sailors and armed men.

Larger ships could carry provisions and support operations beyond the range of galleys, as well as bring more artillery to a fight. In 1478, the Order introduced a large carrack, known as the Great Carrack, to complement its galleys. The carrack Santa Anna, built in 1522, was another ambitious example. These vessels did not make the fleet independent of its supply network: ships had to be maintained, armed and provisioned, and the Order relied on its European revenues and external assistance to meet those costs.

Rhodes was both a fortified base and a maritime power. Its fleet supported the island’s defence and operations in the eastern Mediterranean, while attacks on shipping brought the Order into conflict with Muslim powers and Christian trading communities. The pressure of these competing roles was apparent in the 1522 Ottoman siege, after which the Hospitallers surrendered Rhodes and left the island. Their next permanent base, Malta, would make naval warfare still more central to the Order’s military identity.

Malta: fleets, supply and the corso

Charles V granted Malta and Gozo to the Order in 1530, along with Tripoli in North Africa. The Hospitallers established their headquarters at Birgu, where the harbour provided a base for naval forces. They lost Tripoli in 1551, and the Ottoman siege of Malta in 1565 demonstrated how closely the island’s defence depended on its garrisons, fortifications and connections by sea. After the siege, the Order developed Valletta as its new headquarters, while naval facilities remained centred in the Grand Harbour area.

Maintaining ships required shore-based work as well as crews at sea. An arsenal was established at Birgu in 1597, and the Order’s naval installations included storage, workshops and a bakery for provisions. Shipbuilding took place at Kalkara. Plans for a new arsenal at Valletta were not completed. These facilities supported repair and outfitting, but the Order also depended on financial help from European rulers and institutions. After a tornado destroyed four of its galleys in 1555, replacement ships were funded with contributions from Spain, the Papal States, France and the priory of St Gilles, as well as by the grand master Claude de la Sengle.

The fleet served alongside other European forces, including the Spanish navy. Three Hospitaller ships took part in the Battle of Lepanto in 1571. At other times, the Order pursued the corso, a form of privateering in which ships attacked and captured enemy vessels and cargo. Prize-taking brought income and work to Malta, but it also caused disputes. The Order’s authorities regulated privateering and heard complaints about seizures, including cases in which other powers objected to the capture of ships or cargo connected with Ottoman trade. The practice could therefore serve the Order’s military and financial interests while damaging its relations with trading states.

Over the 17th and 18th centuries, the fleet’s composition changed. Galleys remained important, while larger sailing warships, frigates and ships of the line also entered service. The navy reached a high point in the 1680s, but began to decline after about 1740 as the Order’s wider resources weakened. By the late 18th century, maintaining a military fleet was increasingly difficult. In June 1798, during the French invasion of Malta, a galley, two smaller vessels and a launch made an unsuccessful sortie against French landing forces. With the Order’s capitulation, its remaining ships were taken over by France, ending its naval force.