Since 1940, there have been unfounded claims made about the supposed African ancestry and ethnicity of Charlotte. The inception of this myth was the contention by Jamaican-American writer J. A. Rogers in his book "Sex and Race: Volume I" that she must have a "Negro strain" because of her "broad nostrils and heavy lips", as depicted in the 1761 portrait by Allan Ramsay, and a quote by Horace Walpole describing her "nostrils spreading too wide; mouth has the same fault". This myth expanded over time into varied claims that she had "African" ancestry, including a caricatural observation made in the 1810s by Christian Friedrich, Baron Stockmar, that Charlotte was "small and crooked, with a true mulatto face." This gave rise to subsequent claims that the queen was "mixed-race", "biracial", or "black".