From 1770, Strahan was Printer to the King. Strahan was also the printer for the successful London bookseller Andrew Millar, as well as his longtime friend and business partner. Between 1740 and 1765 Strahan moved his London premises four times in the area between St Bride's and the Strand.
Strahan was appointed as the King's printer from 1770. He also worked for Andrew Millar, a prominent London bookseller and his long-term business associate. Between 1740 and 1765, Strahan relocated his printing shop four times in the vicinity of St Bride's and the Strand.