These open grounds were part of the vast Lands of Blythswood stretching to the River Kelvin acquired by the Douglas-Campbell family in the 17th century.
[1][2] The square's land is part of 10 acres purchased from the Campbells of Blythswood in the 1790s by a calico-printer in Anderston who developed them as Willow Bank.
In 1802 the land and mansion of Willow Bank were bought by "The Great Improver", William Harley, a Glasgow textile manufacturer and merchant.
[1][2] A street plan for the square was drawn up for William Harley by James Gillespie Graham, who was also architect for the Campbells,[3][1][2] but it is thought the facades were ultimately designed by John Brash.
The neighbouring house at the corner of Blythswood Street was the home of 21-year old Miss Madeleine Smith who was tried in the High Court in 1857 of poisoning her lover with arsenic.