This is the FIRST PUBLISHED MAP OF THE ORDNANCE SURVEY, a monumental moment and achievement in British cartography. Despite being published for the Ordnance it was never incorporated into the National Series. The second map to be published and the first of the National Series was that of Essex. Interestingly the Kent was not included until 1816-19 but would still be numbered 1-4. Although the imprint is dated 1 January 1801 its publication appears to have been slightly later according to the advertisement in ‘The Times’ on 13 January. As might be expected with dissected copies the sheets are from mixed states. Here the north-west sheet is state 3, north-east in state 2, south-east state 2 and south-west sheet state 3 according to Burgess. The main roads are coloured in brown as usual and the detail is remarkable. The whole was engraved by Thomas Foot. The Ordnance Survey evolved in 1824 into the format that we are familiar with which ignores county borders. Up to that date the traditional county format was maintained. Burgess (2009) no. 81; Hellyer, Roger (1999) ‘Ordnance Survey small-scale maps’ no. 1.1; Rodger (1972) no. 235.