It "reached into every home in the land, and simultaneously united the nation, an important factor during the Second World War".[177] The BBC introduced the world's first "high-definition" 405-line television service in 1936. It suspended its television service during the Second World War and until 1946, but remained the only television broadcaster in the UK until 1955, when Independent Television (ITV) began operating.[178] This heralded the transformation of television into a popular and dominant medium.