Nelson Thornes' history dates back to 1798 when Thomas Nelson began selling second-hand books in a town square in Edinburgh. In the late 1800s, the company began publishing textbooks and educational literature. By the 1990s it was the largest UK schoolbook publisher. Over the years, the company made a number of acquisitions including Blackie & Son, Harrap and Unwin Hyman ELT. In 2000 Thomas Nelson was acquired by Wolters Kluwer who merged Nelson with its existing publishing arm Stanley Thornes to create Nelson Thornes. The company became a leading educational publisher, producing books and digital resources for the UK, as well as international schools and colleges. Nelson Thornes was acquired in 2013 by Oxford University Press, a department of the University of Oxford.