The world jamborees are organized by the World Organization of the Scout Movement, although the World Federation of Independent Scouts also hold Jamborees for their members.
The Scouting program became an international success following its founding by Robert Baden-Powell in 1907. With its continuing growth, the founder of the movement saw a need for a gathering of representatives of Scouting from all around the world. The general aim was to foster a worldwide brotherhood, and to help the young boys in the movement learn about other peoples and nations by direct interaction with them.
The idea of organizing such periodical international gatherings was originally conveyed to Baden-Powell by the General Chief of the Scouts of Greece, Konstantinos ("Kokos") Melas, during the 1918 international Scout meeting, in England Captain Melas proposed the gatherings should repeat every four years, in the same way Olympic Games were held in Ancient Greece. The suggestion was accepted with enthusiasm by Baden-Powell, who named the gatherings "Jamborees".
However, the outbreak of the First World War in 1914 delayed any plans for such an event. It was not until 1920 that the first World Scout Jamboree could be realized. It was held in the Olympia halls in Kensington, London. Symbolically, the Jamboree site beared the name of the birthplace of the Olympic Games, Olympia. 8,000 Scouts from 34 countries attended the event.
Cartoon in Punch, published in 1929 for the 3rd World Scout Jamboree
Thereafter, a Jamboree has been held every four years. There are two exceptions to this: no Jamboree was held between 1937 and 1947 because of the Second World War, and the 1979 Jamboree, which was to be held in Iran, was cancelled due to the political upheaval in the region at that time. The Jamboree has been held in different countries around the world. The first seven Jamborees were held in Europe. The eighth World Jamboree was held in North America where the tradition of moving the Jamboree among the continents began. As yet, the continent of Africa has not hosted a jamboree.
To replace the cancelled event of 1979, the World Scout Committee determined that an alternative celebration, the World Jamboree Year should take place. Several regional camps took place, along with countless Join-in-Jamboree activities — designed to allow Scouts from around the world to participate in an activity that thousands of other Scouts around the world were also participating in at the same time. This Join-in programme is being reproduced again as part of the Scouting 2007 Centenary celebrations.
So far, the greatest attendance of all Jamborees was in 1929, where over 50,000 members from around the world descended upon Birkenhead in the north-west of England. This number represented the permanent contingent who remained for the entire event. They were joined by hundreds of thousands of visiting Scouts who participated on a day basis.
The first Jamboree was more akin to an exhibition of Scouting, allowing visitors to see how things were done in other parts of the world. The Second Jamboree was conducted on a camp basis and each successive Jamboree has developed on this format where the program is typically more activity oriented, with plenty of time for Scouts from different nations to interact and learn about each other in less formal ways than an exhibition would allow.
The 2007 Jamboree coincided with the Scouting Centenary celebrations. Because of this, the honour of hosting the event was again bestowed upon the United Kingdom, as the birthplace of Scouting. Over 40,000 young people camped in August at Hylands Park in Chelmsford, Essex. Hundreds of thousands of day visitors attended events in the south-east of England as part of the Jamboree.
The next Jamboree will be in 2011 in Sweden, the Jamboree in 2015 will be in Japan and the Jamboree in 2019 will be at The Summit Bechtel Family National Scout Reserve.