into a virtual entity (the "Virtual Centre"). History Skyguide traces its origins back to 1922, when, after the First World War had demonstrated the importance of telecommunications, Switzerland concluded an agreement with the Marconi company. Swiss subsidiary Marconi Radio AG was founded on 23 February of that year to develop wireless telegraphy. On 10 May 1928, the company name was changed to Radio Schweiz AG (RSAG) to emphasize its Swiss national character. And on 1 January 1931, the Swiss Confederation mandated Radio Schweiz to provide air navigation services in Switzerland. Up until the end of the Second World War, Radio Schweiz was primarily engaged in meeting the telegraphic communications needs of the Swiss Confederation. Only on 21 December 1948, after concluding an agreement under which the Confederation and the country's airports would bear the costs of air navigation services, did Radio Schweiz start to monitor Swiss airspace. On 1 January 1989, Radio Schweiz's air navigation activities were restructured and brought into the new Swisscontrol company, whose headquarters were in Bern. Swisscontrol was converted into a public limited company in 1996, and its headquarters were transferred from Bern to Geneva. At the beginning of 2001, military air navigation services, which had been provided separately until then, were also placed under the responsibility of Swisscontrol, which was renamed skyguide in the process. Skyguide thus became the first air navigation service provider in Europe to control the whole of its country's airspace. On 1 July 2002, a Tupolev Tu-154 of BAL Bashkirian Airlines of the Republic of Bashkortostan in Russia and a Boeing 757 of DHL Express collided in Überlingen near the German-Swiss border at an altitude of 12,000 metres in skyguide-controlled Southern German airspace. 71 people died. Four skyguide employees were subsequently sentenced by a court. On 24 February 2004, Peter Nielsen, the air traffic controller who had been on duty at the time, was stabbed to death by Vitaly Kaloyev, who had lost his wife and two children in the accident. On 21 September 2005, skyguide became one of Europe's first air navigation service providers to be certificated companywide to the ISO 9001:2000 norm. In achieving this, skyguide also met the requirement for Single European Sky (SES) certification.[10] On 15 March 2006, skyguide was adjudged to have not met the requirements for operating a single control centre for Switzerland's upper airspace. The project concerned did, however, allow the management of Geneva