Please answer the following question: Given the following context:  George Frederic Watts was born in 1817, the son of a London musical instrument manufacturer. His two brothers died in 1823, and his mother in 1826, giving Watts an obsession with death throughout his life. Watts was apprenticed as a sculptor at the age of 10, and by his mid-teens was proficient enough as an artist to be earning a living as a portrait painter. At the age of 18 he gained admission to the Royal Academy schools, although he disliked their methods and his attendance was intermittent. From 1837, Watts was successful enough to devote himself full-time to painting.In 1843 Watts travelled to Italy where he remained for four years. On his return to London he suffered from melancholia, and painted many notably gloomy works. His skills were widely celebrated, and in 1856 he decided to devote himself to portrait painting. His portraits were extremely highly regarded, and in 1867 he was elected to the Royal Academy, at the time the highest honour available to an artist, although he rapidly became disillusioned with its culture. From 1870 onwards he became widely renowned as a painter of allegorical and mythical subjects; by this time, he was one of the most highly regarded artists in the world. In 1881 he added a glass-roofed gallery to his home at Little Holland House, which was open to the public at weekends, further increasing his fame.  answer the following question:  What is the last name of the person whose two brothers died in 1823?
A:
Watts