The rear of this old house was built not long after 1450, replacing an earlier wooden construction. The frontage was added around 1472 and subsequent additions, floors and modifications have been made ever since. James Mossman, who was a goldsmith and keeper of te Royal Mint to Mary, Queen of Scots, was responsible for a substantial reconstruction.
Although John Knox, the great reformer of the church in Scotland, lived at this time, there is no record of him ever staying in this house. But, over the years, the legend evolved that he had given one of his thundering orations to the people of Edinburgh from a bow-window on the house, overlooking the High Street. By 1800 it was confidently being described as "John Knox's House" and guide books ever since have described it in this fashion.