Complex sentence: In 1936 he divorced his first wife and married Dorothy Rudge Roberts, by whom he had two children; the marriage survived until Pritchett's death in 1997, although they both had other relationships.
Split into simpler sentences: In 1936 he divorced his first wife and married Dorothy Rudge Roberts, with whom he had two children. The marriage lasted until Pritchett's death in 1997, although they both had other relationships.