Charles James Smithem was was born in London, England on 10 November 1856 and was articled to Nathan Solomon Joseph (1834-1909) in London from 1870 to 1876. He worked as an assistant to Joseph and George Pearson (1846-1934) from 1876 to 1884.
In 1885 he went into partnership with Joseph as Joseph & Smithem. Joseph's son, Charles Sampson Joseph (1872-1948), subsequently joined the practice which was renamed Joseph, Son & Smithem. The partnership was dissolved on 31 December 1903. It appears to have been re-formed as Joseph & Smithem with Charles Sampson Joseph, Charles James Smithem and Ernest Martin Joseph (1877-1960) [son of Nathan Solomon Joseph] as partners. This partnership was dissolved in 31 December 1916.
Smithem was elected a Fellow of the Royal Institute of British Architects (FRIBA) in 1894. He was also Master of The Worshipful Company of Tylers and Bricklayers of the City of London in 1920-21. He died on 28 September 1937.
See Historic England [link below]
Directory of British Architects 1834-1914. Compiled by Antonia Brodie, et al. Volume 2: L-Z. London; New York: British Architectural Library, Royal Institute of British Architects/Continuum, 2001