Mabeth was born in Greenock in 1821. He served as an apprentice engraver in Glasgow for seven years, then went to London, where he studied at the Royal Academy. He later moved to Paris, where he worked in the Louvre. After returning to Scotland, in 1845 Macbeth established himself as a portait painter, and exhibited regularly at exhibitions at the Royal Scottish Academy. Around two years before his death, he moved to London, where he represented the Royal Scottish Academy as a trustee of the British Institution Scholarship Fund. He died there on the 27th February, 1888.