A little over 900 years ago the Abbey of St. Mary in Jerusalem set up a small hospital to care for sick pilgrims. The hospital was attached to a little church dedicated to St. John and run by monks from the local Benedictine Abbey. The subsequent capture of Jerusalem in 1099 during the First Crusade and establishment of a Christian Kingdom, encouraged even more pilgrims to visit.

The Hospital quickly benefited from many gifts of property in Europe as well as in the east. Eventually the monks began to move away from their Benedictine origins and in 1113 Pope Paschal acknowledged the autonomous new order of the Hospital of St John of Jerusalem. The Hospitallers, both brothers and sisters, took vows of poverty, chastity and obedience. Their main aim was to care for the sick.

The Brothers of St. John later developed a military role. By the middle of the twelfth century, the Order of St. John was a military religious order whose members vowed to care for the sick as well as defend Christianity. The trend in healthcare started by the Hospitallers finds echoes today, they believed that the best way to recovery was through good nursing care and hygiene; with surgery only if absolutely necessary.

The Order of St. John flourished across Europe, with devout Christians continuing the tradition of giving money and property to the Hospital in Jerusalem to carry out God’s work. In about 1140, its Knights in Britain built their headquarters in Clerkenwell, London. By the second half of the twelfth century, the Order has become firmly established in West Wales. In the last decade of the twelfth century, land of the Manor of Dolgynwal in North Wales, was given to the Order. Around 1225, Llywelyn the Great made gifts of estates in Shropshire.

In 1511 Henry VIII was given responsibility for the orders of the Roman Catholic church in Great Britain, including the Order of St John. When the Church of England was established he failed to uphold this responsibility, instead he seized their assets and confiscated the lands which had been given to the Order over many years. This spelt the end of the medieval English Priory.

The Order of St John of Jerusalem continued in Catholic Europe, although it faced a difficult period after the loss of its headquarters in Malta in 1798. In the wake of that disaster, some members of the order decided, on their own initiative, to revive the British branch. This was not accepted by the head of the order in Italy, but the British organization survived, with members determined that the Hospitaller tradition of caring for the sick should return to England.

In 1877 the St John Ambulance Association was founded; when Britain was at the height of the industrial revolution. Work was often unpleasant and dangerous, and accidents frequent. St. John Ambulance decided to train ordinary people to give assistance on the spot. They ran classes on First Aid, published books and other material and set examinations for First Aid certificates. This proved to be very popular even outside the heavily industrialised areas. The organisation grew from factories, spreading to villages and more affluent suburbs.

Before long thousands of people had received their First Aid certificates and many of them wanted to use their training to help the public. At first they got together in groups called Ambulance Corps, then in 1887, the St. John Ambulance Brigade was formed. Its aim was to provide a service of First Aid and ambulance transport at public events. Members attended ‘wherever crowds gathered’ from great national occasions to local football matches. (Later, the Brigade and Association merged as "St. John Ambulance".)

In 1882, the British Order acquired land in Jerusalem to set up an Eye Hospital, which has been operating ever since. In 1888, in recognition of its work, Queen Victoria made the British Order of St. John a Royal Order of Chivalry with the title ‘The Most Venerable Order of the Hospital of St. John of Jerusalem’. (King George V, an enthusiastic supporter, added “Most” to the formal title.)

In the 1890s the medieval ceremonial sword of the Hospitallers in Wales was discovered and is still used at all important ceremonial occasions of the Order of Wales. The Order soon spread throughout the then British Empire bringing western medical techniques to the colonies. The First Aid message proved more permanent than the spreading of British “values and virtues”. In many places St John Ambulance classes appeared as a part of training on the railways, docks and as a part of police work. St John Ambulance remained in many places long after Independence.

In wartime St John Ambulance and the Red Cross worked together meeting various health needs of soldiers. The Joint War Committee was established as a result of the public horror at events during World War I. Together the organisation provided trained volunteers and reserves for Army hospitals and later an extensive network of medical services were set up in Britain and on the front lines.

n 1907 King Edward V11 had authorized the Grand Prior to establish new priories in Great Britain and the Empire. The first priory to be established as a result of this was Wales in 1918

Involvement in the war effort continued in World War II, with St John and the Red Cross again joining forces to provide welfare services. These included an anti-gas training programme, First Aid posts in London’s tube, and the training of volunteer nurses. St John as recently as 2003, in the Gulf War, sent aid workers to the front lines.

St John is now active in nearly 40 territories around the world. Separate Priories were established in Scotland, Wales, South Africa, New Zealand, Canada and Australia. They were joined by the United States in 1996. In October 1999, as part of major constitutional changes in the Order, the Priory of England and the Islands was created to take its place alongside the other seven. The leaders of the 8 Priories with the 5 Great Officers (Senior Order Volunteers) together form the ruling body of the Order, the Grand Council. There are also 32 Associations around the world.

The Order Secretariat, led by the Secretary General, came into existence in October 1999 to support the Grand Council, and to act as a link between the Priories, St John Associations and the Foundation for the Jerusalem Eye Hospital.