He married twice: 1. Sarah Newbould Spur, by whom he had two children. 2. Jane Muir, by whom he had six children.
A self-educated man from Aberdeen, he went to St Petersburg in 1822. In 1843 he founded an import business. In 1852 he formed a partnership with Andrew Muir of Greenock. By the late 1880s the firm 'Muir and Mirrielees' had transferred its operations from St Petersburg to Moscow, and in 1891 it became a purely retail concern. After Mirrielees' death 'Muir and Mirrielees' became to Moscow what Selfridges was to London or Jenners to Edinburgh. He was a religious man, and his second wife was a close friend of AMW at St Petersburg.
Pitcher, Harvey, Muir & Mirrielees: the Scottish Partnership that Became a Household Name in Russia, Cromer, 1994.