The British Transport Police (BTP) is a national special police force that polices the United Kingdom's railways and light-rail systems. Founded on 1 January 1949 as the British Transport Commission Police (BTCP), the agency had national jurisdiction, including the London Underground, Emirates Air Line, and Eurostar; however, the BTP did not have jurisdiction in Northern Ireland, but rather the Police Service of Northern Ireland. In 2016, the BTP had 5,127 personnel.