Silicon Fen also known as the Cambridge Cluster, is the name given to the region around Cambridge, England, which is home to a large number of high tech businesses focused on software, electronics, and biotechnology, including Arm and AstraZeneca. The name Silicon Fen originated as an analogy with Silicon Valley in California because it lies at the southern tip of the English Fenland. The local growth in technology companies started with Sinclair Research and Acorn Computers. More than 1000 high-technology companies established offices in the area during the five years preceding 1998. Some early successful businesses were Advanced RISC Machines and Cambridge Display Technology. In 2004, 24% of all UK venture capital, representing 8% of all venture capital in the European Union, was received by Silicon Fen companies, according to the Cambridge Cluster Report 2004 produced by Library House and Grant Thornton. The so-called Cambridge phenomenon, which gave rise to start-up companies in a town that previously had only light industry in the electrical sector, is usually dated to the founding of the Cambridge Science Park in 1970 as an initiative of Trinity College at the University of Cambridge. The characteristic of Cambridge is small companies in sectors such as computer-aided design. They are spread over an area defined by the CB postcode or 01223 telephone area code, or more generously in an area bounded by Ely, Newmarket, Saffron Walden, Royston, and Huntingdon. In 2000, then Chancellor of the Exchequer Gordon Brown set up a research partnership between MIT and Cambridge University, the Cambridge–MIT Institute, in order to increase international collaboration between the two universities and strengthen the economic success of Silicon Fen. In February 2006, Cambridge Judge Business School reported estimates that there were approximately 250 active start-ups directly linked to the university, valued at roughly US$6 billion. Several of these companies have grown into multinationals, including Arm, Autonomy Corporation, AVEVA, and Cambridge Silicon Radio.