The London Underground 1973 Stock is a type of rolling stock used on the Piccadilly line of the London Underground.It was introduced into service in 1975 with the extension of the line to Hatton Cross, followed by a further extension to Heathrow Central in 1977. A total of 86 six-car trains were built. The trains were built by Metro-Cammell between 1974 and 1977, and were …

The Northern Ireland border poll was a referendum held in Northern Ireland on 8 March 1973 on whether Northern Ireland should remain part of the United Kingdom or join with the Republic of Ireland to form a united Ireland.It was the first time that a major referendum had been held in any region of the United Kingdom.The referendum was boycotted by nationalists and resulted in a …