Invented the milk churn and campaigned for cleaner milk. Son of a dairyman. In 1864 in Museum Street/Coptic Street established the Express Country Milk Supply Company which sold milk. He also established The Dairy Supply Company which didn't sell milk but supplied dairy-related items such as, oh yes, milk churns. About the milk supply company Wikipedia says: " It was the first British Dairy to use glass milk bottles, the first to use milk churns and glass lined tanks to carry 30 0000 gallons of milk by train into London every night and one of the first to introduce pasteurisation to sterilise milk. It even supplied milk to Queen Victoria. For his services the owner and managing director George Barham Sr. was knighted in 1904." Note that it's only the British who use 'churn' to mean 'large milk container'. The Americans have something called a 'butter churn' in which milk is agitated to form butter. That common language - getting in the way again.
The Camden History Society Review no 36 contains a splendid piece on the milk trade and there we learn that Barham was probably born at 2 Crown Court in the City. He became chairman of the British Dairy Farmers' Association. Barham lived on Haverstock Hill, Hampstead for many years and was Mayor of Hampstead 1905-6. His wife (the Mayoress) died during this term, after which Barham lived mainly at his Sussex home. the Review has a (copyrighted) picture of Barham.