. The desire for an heir added strain to the Spencers' marriage, and Lady Althorp was reportedly sent to Harley Street clinics in London to determine the cause of the "problem". The experience was described as "humiliating" by Diana's younger brother, Charles: "It was a dreadful time for my parents and probably the root of their divorce because I don't think they ever got over it." Diana grew up in Park House, which was situated near to the Sandringham estate.