[4] In 1789 William Harley moved to Glasgow, becoming a textile manufacturer, employing some 600 handloom weavers in partnership with a fellow member of the Merchants House but soon opened his own business warehouse on the corner of George Square on South Frederick Street.

[5] By 1802, and now married to Jane Laird of Greenock, his business was so profitable that he purchased a house called Willowbank and ten acres of land adjacent to the future Sauchiehall Street from Lawrence Phillips of Anderston.

[5] William Harley employed stonemason firms to build the first terraces of townhouses which were along the southside of Sauchiehall Street, and erected before 1815.

In the 1820s he devised and laid out Blythswood Square, adjacent to his 10-acre Willowbank pleasure gardens which were, open to paying members of the public.

This attracted attention from home and overseas including Nicholas I of Russia, Archdukes John and Louis of Austria,[4][1][3][2][7] He was asked by the Highland Society of Scotland to write a book on his methods[7] which he finally published in 1829, a year before his death in London.

[4][8][1] William Harley continued to run his businesses as they struggled for a year or two thereafter, but then they were placed in a trust formed by some contemporaries in an attempt to keep them going.

Graeme Smith wrote a biography of William Harley and family and the development of Glasgow's New Town of Blythswood from 1800 to the present day, in 2021.

[4][5] In 1829 he was invited by the Tsar of Russia to manage and improve the new Imperial dairy in Saint Petersburg, but while travelling he took ill and died in London.