The bas reliefs depict four famous people with Derby associations. William Hutton was an English poet and historian. Originally from Derby, he moved to Birmingham and became the first significant historian of the city, publishing his History of Birmingham in 1781. John Lombe was a silk spinner in Derby in the eighteenth century century and transformed silk manufacture in Derby from a cottage industry to a more organised form of manufacture. Erasmus Darwin was a Physician, Botanist and Poet who lived in Derby for the last 20 years of his life. Herbert Spencer, born in Derby, was a philosopher, radical, pioneer, sociologist, educationalist and supporter of Charles Darwin.