These letter books cover the business of the Thornbush Brewery in Inverness. In 1887, James Lyon Guild (1852-1925) and his brother-in-law Richard Wyllie (1854-1944) established Guild and Wyllie to run the brewery. The partnership was dissolved in 1894, after which time James Lyon Guild ran the business himself as Guild and Co. until 1913 when the brewery was sold at auction.

The copy letter books here were kept by James Lyon Guild and cover the running of the business, the breakdown of the partnership and some personal letters.