Complex sentence: In 1830 the "Irish Unitarian Society (for the Diffusion of Christian Knowledge)" now the "Irish Unitarian Christian Society" was formed among its founders was Rev. Dr. James Armstrong, promoted Unitarianism particularly in the South of Ireland by publishing Books and other works.
Split into simpler sentences: In 1830 the "Irish Unitarian Society (for the Diffusion of Christian Knowledge)" now the "Irish Unitarian Christian Society" was formed. Among its founders was Rev. Dr. James Armstrong, who promoted Unitarianism particularly in the South of Ireland by publishing books and other works.