John Maynard Smith
In 1917, he married Isabel Mary Pitman, daughter of Frederick I. Pitman. They had a daughter Isabel Valentine Maynard Smith (born 1919), and a son, the biologist John Maynard Smith (1920-2004). In later life John Maynard Smith described his father as being "a poor boy made good" who married into "landed gentry", and recalled of their relationship prior to Sidney's death when John was eight years old "I hardly knew him; we saw him sort of Sunday lunch - literally". He and his family lived at No. 49 Wimpole Street in Westminster