Arthur Sullivan was an English composer who is best known for his collaboration with the librettist W.S. Gilbert. Together they produced a series of comic operas that became immensely popular in the late 19th century, including 'H.M.S. Pinafore', 'The Pirates of Penzance', and 'The Mikado'. Sullivan's compositions combined catchy melodies with witty lyrics, creating a unique blend of satire and musical charm. He was also a successful composer of sacred music and orchestral works, showcasing his versatility and talent.