Introduction

A “field hospital” is a mobile medical unit, which temporarily takes care of casualties on site before they can be safely transported to more permanent hospital facilities. Traditionally, field hospitals were military units located close to battlefields and included physicians and surgeons who could cope with most of the medical conditions.

In the ancient world, the ability of the medical profession to cope with health problems was limited. The concept of hospitalization – caring for sick and wounded people in a special medical institution – was unknown, neither to the civilian society, nor to the military. During the battles of early empires or even in the Hellenistic world, military medicine was represented only by physicians, whose main task was to extract arrows or other foreign bodies from tissues. There was no medical service of the military organization, including no form of hospital.

Rome

The first time in the history of the Western world that hospitalization (meaning the organized care of sick and wounded patients) is noted was in the Roman army. In the eyes of the Roman-army commanders, care of the wounded was considered as a military necessity, not only because it allowed better chances to overcome the medical problem but mainly as a solution for coping with demoralization of the troops[1].

During the epoch of republican Rome, battles were fought near to home. At that time, the Roman army had no medical arrangements for the care of the sick and wounded soldiers beyond wound dressing. The more serious cases were left at patrician houses for care and recuperation. When the Roman legions began to fight at remote battlefields and in unfriendly territories, casualties could not be left to be cared for by the local population anymore.

It was the Emperor Augustus in the first century AD who understood the importance of providing medical care for his troops by an organized medical service. The solution was the establishment of a system of hospitals – valetudinaria – located along major Roman routes and at crucial occupied areas in various provinces. Some historians consider these military hospitals as “the greatest Roman innovation in medicine[2].”

Valetudinaria were the answer to the medical problems of the remote legions. They were an integral part of legion camps and forts all over Europe. They were, most probably, built to accommodate the sick, but injured soldiers were also treated there. Surgical instruments found in archeological excavations of valetudinaria proved that surgical work was performed in them[2].

During the imperial period, it became standard practice to include a hospital in any legion camp or fort. These were always ready to accommodate and treat as many as 2.5–10% of the legion[2]. The professional head of the hospital was a medical officer who reported to the camp commander. The hospital team included physicians, surgeons, and medics.

The valetudinarium was constructed as a square structure, built of stone, and was 90 m × 50 m in dimension. It was divided into four quadrangles, which enclosed an inner courtyard. These included the patients’ wards. The valetudinarium could accommodate 200–220 patients in 38 rooms. The entrance hall led to a large hall, most probably a reception room, and to treatment rooms, baths, the kitchen, and the medical depot[2].

No records of the many valetudinaria have survived. Thus, the professional work that was done in these hospitals cannot be estimated. However, the assumption that these kinds of medical facilities served as the first field hospitals in the Western tradition is quite solid.

Byzantium

Many aspects of Rome’s legacy were transferred to its Eastern successor: the Byzantine Empire. The military tradition was one of these aspects, including the medical services of the military organization. Thus, for many years the Byzantines continued to use the traditional Roman military hospital: the valetudinarium.

When Emperor Maurice (582–602) changed the nature of the Byzantine army by integrating infantry soldiers and mounted horsemen, the nature of the medical service in the field was also changed. In every regiment of 300–400 soldiers (numerus), a new medical unit was established. This unit included one physician and one surgeon, and 8–18 medics and stretcher bearers.

The Byzantines were the first in the Western civilization to establish general hospitals. These hospitals served both the military and the general population. They also considered the preservation of military ability as being crucial. However, they never attempted to establish hospitals for their armies in the field. The great medical centers that served the military community, according to the best professional standards of the time, were located only in the cities. Wounded and sick soldiers were treated at these hospitals[3].

Crusaders’ Kingdom of Jerusalem

The Crusaders’ Kingdom of Jerusalem was in an intermittent state of war with the neighboring Muslim states for almost two hundred years. Its unique innovation was the creation of the military orders. The first among them, the Order of the Knights of Saint John of Jerusalem (The Hospitallers), was established to care for sick and poor Christian pilgrims in the Holy Land and later to protect the Crusaders’ Kingdom. The greatest achievement of the Order was the foundation of the hospital in Jerusalem. The concept of a “hospital” was unknown in Europe at that time and it is assumed that the hospital in Jerusalem reflected direct Byzantine influence[4]. The hospital served the population as a general hospital, but it also maintained its military obligations.

After the battle of Tel Gezer[5] in 1175, where Saladin was defeated by the Crusaders, 750 Christian battle casualties were evacuated from the battlefield and were admitted to the hospital in Jerusalem. This event demonstrated two facts: the first was the hospital was able to cope with a huge number of casualties without being overwhelmed. The second was that there were no field hospitals in the Crusaders’ Kingdom[6].

Medieval Times

No medical service can be detected in European and other military organizations during the Middle Ages. A wounded soldier was bandaged by a comrade or by a medic and, in some cases, a foreign body was extracted from the soldier’s tissues by a physician. No further medical or surgical treatment was expected to be given as hospitals usually did not exist. In many battles, there may have been a surgeon accompanying a king or a prince, but there was no medical service for the troops. However, some developments are noticed: at the start of the Hundred Years’ War, at the Battle of Crécy in 1346, Edward III of England was accompanied by the surgeon John de Arden, but there was no medical personnel for the troops. Almost 70 years later, at Agincourt, 1415, Henry V was accompanied by the surgeon Nicholas Colnet, while Thomas Marstede was appointed army surgeon with 12 assistant surgeons: all were paid to look after the soldiers[1].

The first evidence of a field hospital during military operation can be found in the chronicles of the siege of Granada – the last stand of the Muslims in Spain – in 1484. As far as we know, the establishment of a field hospital for the sake of the sick and wounded soldiers was Queen Isabella’s own idea:

Queen Isabella’s grandson, King Charles V, followed his grandmother’s example: in his armies, the sick and wounded soldiers were evacuated from the battlefield to the baggage trains and put into tents, a kind of field hospital. There, they were attended by physicians or surgeons.

Renaissance and the Religious Wars in Europe

During the fifteenth and sixteenth centuries, gunpowder weapons replaced sharp-edged weapons and became important developments in military medicine. While in the fifteenth century the professional consensus was that all wounds produced by projectiles were poisoned, this notion was challenged during the sixteenth century. It was Bartolomeo Maggi (1477–1552) who was probably the first not to accept the theory of the poisonous nature of gunshots. He was also the first to advocate that amputation due to gangrene should be performed through the living flesh. At the same time, the military surgeon Ambroise Paré (1510–1590) changed the attitude to the treatment of wounds caused by firearms (1545) and reintroduced the use of ligature, which allowed better outcome of amputations.

All these developments and innovations occurred at the level of the individual surgeon, treating wounded soldiers at the battlefield. At that time no link was established between professional innovations and organizational changes leading to a better performance of medical services at the battlefield. It should also be mentioned that the great discoveries in the field of medicine – such as Harvey’s discovery of the circulation of the blood and the microscope of van Leeuwenhoek and others – had no impact on the practice of medicine and surgery in general, and on military medicine in particular during the seventeenth century.

The religious wars took place during the sixteenth and seventeenth centuries in Europe. They manifested themselves in a variety of conflicts, from local disputes to full-scale long and devastating wars, such as the Thirty Years’ War (1618–1648). From professional medical and surgical points of view, no significant advances occurred during this epoch. However, some steps were taken in the direction of better organization of military medicine in the field:

The first organized military hospitals in Germany were those authorized by the Elector Maximilian I, the Duke of Bavaria, in 1620, for the Catholic League. These hospitals were not mobile, but they were located close to the battlefield and thus named “field hospitals.” One of them represented a new concept: it was designed to give the necessary medical treatment to battle casualties at the field and to enable them to be evacuated to a permanent military hospital. Thus, it was one of the first military hospitals to function as a clearing hospital[7].

In the Spanish Army of Flanders during the late sixteenth century, there was no medical service in the field. To the commanders and doctors of that army, it seemed a big hospital at Mechelen, Belgium, may solve the health problems of the troops. It became an issue only when, in the seventeenth century, the army command realized that sickness and injuries among the troops, when not attended properly, may encourage desertion and discourage civilians from joining the services[8]. It brought about the establishment of field hospitals, which had very limited professional abilities: they were expected to give the wounded and sick soldiers only initial treatment and then to transfer them to a fixed rear hospital.

The rise of military medicine in England began with the establishment of the standing army. The army was organized into regiments, and every regiment had a surgeon and an assistant surgeon. The task of these professionals, augmented by soldiers from the regiment itself, was to treat 40 patients at the battlefield and then to evacuate them to base hospitals in the rear.

Field hospitals – the missing link in efficient medical evacuation from the battlefield to rear hospitals – did not appear in England until 1690, during King William III’s campaign in Ireland. These hospitals were designed to accompany the armies and thus were called “marching hospitals” or “flying hospitals”[7].

The main task of the marching hospital was to be ready to treat battle casualties evacuated from the regiments, as close to the front line as possible. Later, they were meant to either further evacuate the patients to hospitals in the rear or keep them until they recovered. The marching hospital unit was independent logistically: the hospital consisted of 12 horse-drawn carts, which carried 25 tents. After the hospital had been erected, the carts evacuated casualties to the fixed hospitals. Overall, when assembled, the hospital could accommodate up to 200 patients and it carried all necessary surgical and medical equipment. It was expected that, during active fighting, the marching hospital would be located beyond the range of cannons: less than 2 km from the firing line[9]. The hospital had 17 staff officers: one physician, one master surgeon, eight surgeon’s mates (assistants), one master apothecary, three apothecary’s mates for dispensing duties and care of medical stores, and three purveyors for commissariat duties[7].

The flying hospital had proved successful in the War of the Austrian Succession when it acted as expected: an essential link between the regimental medical teams and the general hospitals.

The Duke of Marlborough, one of the most distinguished British military commanders in history, was exceptional in his attitude toward the health of his troops: during his march to the Danube (1704), he was involved in the details of the medical plan. The duke insisted on having at least one medical officer in every regiment, foot or horse. Most regiments also had a surgeon’s mate. The duke’s force was followed by at least one field hospital[10].

The Eighteenth Century

Several military developments may be noted at the battlefields of the eighteenth century: improvements in firearms and in military tactics created new battlefields where, at every engagement, large numbers of casualties were expected. However, advances in military surgery improved the soldier’s chances of overcoming injuries when treated properly close to the front line. The increasing size of the armies forced the various state governments to recognize their responsibility in giving proper medical care to their troops. Thus, in most armies, permanent medical services were established. The medical services included regimental hospitals: those small medical units attached to combat units, which gave immediate medical treatment to battle casualties. In some military organizations were also the flying hospitals: marching hospitals whose personnel were better qualified than the personnel of the regimental hospitals. During sieges, the French army utilized special field hospitals, naming them “hospital ambulant.” Casualties evacuated from the regimental hospitals were treated at these hospitals. They were further evacuated to fixed hospitals located in towns and cities[1]. This concept was adopted by the Russian army during the reign of King Peter the Great[1]. Though casualties were given best-available treatment at various hospitals, one of the sustained problems was lack of organization of the evacuation of casualties from the battlefield.

There were exceptions: during the War of the Austrian Succession, the British medical service treated the wounded on the front line and collected them at ambulance stations. Surgeons performed surgical procedures at the forward medical stations situated behind the front line and then evacuated the more seriously wounded to hospitals in nearby towns[7].

In the newly established USA, the standard of medicine generally was low, and the War of the Rebellion began without any permanent structure for medical care. Only during the war itself, and due to congress delegates’ requirements, was the European structure of military medical service approved. It included regimental hospitals, flying hospitals, and fixed hospitals[11].

The Napoleonic Wars (1792–1815)

During the Napoleonic Wars, huge armies were exploited in the field. Due to new tactics and the massive use of artillery, the number of battle casualties became huge. Wounded soldiers could remain unattended for long hours on the battlefield and, when they were at last evacuated to base hospitals, transportation in specially designed wagons took more than 24 hours. The lag period until evacuation from the battlefield, combined with the long and tedious evacuation process itself, were among the factors that contributed to a high mortality rate among battle casualties.

Baron Pierre-François Percy (1754–1825) introduced to the French Army of the North a corps of trained stretcher bearers; their task was to pick up wounded soldiers and carry them to the nearest aid post. He also introduced horse-drawn wagons to the army, designed for the treatment and evacuation of battle casualties. Every wagon was staffed by surgeons and surgical teams with adequate surgical equipment, who were able to give medical treatment to casualties at the field and during the evacuation to the rear[12].

Baron Dominique Jean Larrey (1766–1842), the chief surgeon of the Grande Armée, and who participated in most of the Napoleonic campaigns, went even further. He introduced to the medical service in the field the ambulance volante: the “flying ambulance”[1]. This was not a new version of the old flying hospital – the field hospital that served as a midlink between the regimental hospital and the fixed hospital – Larrey actually introduced a new concept to military medicine, and to medicine in general: the importance of time. Until Larrey’s innovation, throughout the history of military medicine, battle casualties had been evacuated from the front line only after the battle was over. Larrey, a military surgeon with vast experience at many battles, realized that the earlier a wounded soldier was treated, the better the prognosis. It meant that the modus operandi of the ambulance volante was to treat casualties at the battlefield itself and even under fire. Thus, Larrey, by bringing the hospital to the soldiers, recognized time as an important independent prognostic factor and became the father of future emergency medicine.

The flying ambulance consisted of 340 men, organized into 3 divisions of around 113 each. It included a chief surgeon, 15 other surgeons, and 5 members of the quartermaster corps. It also included a trumpeter, whose task was to carry the surgical instruments, and a drummer boy in charge of the surgical dressings. Each division also had 12 light and 4 heavy carriages[1].

The parallel figure in the British army to Larrey in that same period was James McGrigor, who served as the principal medical officer of the Duke of Wellington during the Peninsular War. McGrigor believed the process of evacuation of sick and wounded soldiers was tedious and that, in many cases, they were treated too late. He suggested to Wellington the establishment of field hospitals as backup medical units to the regimental hospitals. However, Wellington rejected this idea because he considered any slow-moving transport as compromising his tactical freedom. The outcome was that McGrigor established a chain of general hospitals in various places in the Peninsula[1].