Michael Dahl's original portrait of Catherine Shorter (ca. 1682-1737) was painted before the sitter became Lady Walpole in 1725. The granddaughter of a Lord Mayor of London, Lady Walpole had produced five children for Sir Robert in the six years following their marriage in 1700. By the time Horace was born in 1717, Lady Walpole's relationship with Sir Robert was strained. Horace grew up adoring his mother and rather disliking his father whose political genius he began to appreciate only in the last years of Sir Robert's life.