brother George got apprenticed to Baird in the early 1840s. In September 1847 Thomson married Jane Nicholson, and on the same day her sister married another architect, John Baird (unrelated to Thomson's employer, and referred to by biographers as John Baird II), who fell out with his previous partner. In 1848 Thomson joined him in a new partnership, the practice of Baird & Thomson. In 1857, as "the rising architectural star of Glasgow," he entered into practice with his brother George where he was to enjoy the most productive years of his life. He served as president of both the Glasgow Architectural Society and the Glasgow Institute of Architects. Thomson was an elder of the United Presbyterian Church of Scotland, and his deep religious convictions informed his work. There is a strong suggestion that he closely identified Solomon's Temple with the raised basilica of the same form of his three major churches. He produced a diverse range of structures including villas, a castle, urbane terraces, commercial warehouses, tenements, and three extraordinary churches. Of these, Caledonia Road Church (1856–57) is now a ruin, Queen's Park United Presbyterian Church (1869) was destroyed in WWII, and St Vincent Street Church (1859) is the only intact survivor. Hitchcock once stated, "[Thomson has built] three of the finest Romantic Classical churches in the world”. Thomson developed his own highly idiosyncratic style from Greek, Egyptian and Levantine sources and freely adapted them to the needs of the modern city. At the age of 34, Thomson designed his first and only castle, Craigrownie Castle, which stands at the tip of the Rosneath Peninsula in Cove, overlooking Loch Long. The six-storey structure is Scots Baronial in style, featuring a central tower with battlements, steep gables and oriel windows, in addition to a chapel and a mews cottage. Thomson's villa designs were realized at Langside, Pollokshields, Helensburgh, Cove, the Clyde Estuary, and on the Isle of Bute. His "mature villas are Grecian in style while resembling no other Greek Revival houses,...[and they] are dominated by horizontal lines and rest on a strong podium." According to Gavin Stamp, "Thomson carefully designed his villas with symmetries within an overall asymmetry in a personal language in which the horizontal discipline of a continuous governing order—whether expressed or implied—was never abandoned. Regarding similarities to Frank Lloyd Wright, Stamp states, "It has often been remarked that there are clear resemblances between the early houses