Background: Gilbert and Sullivan refers to the Victorian-era theatrical partnership of the dramatist W. S. Gilbert (1836-1911) and the composer Arthur Sullivan (1842-1900) and to the works they jointly created. The two men collaborated on fourteen comic operas between 1871 and 1896, of which H.M.S. Pinafore, The Pirates of Penzance and The Mikado are among the best known. Gilbert, who wrote the libretti for these operas, created fanciful "topsy-turvy" worlds where each absurdity is taken to its logical conclusion--fairies rub elbows with British lords, flirting is a capital offence, gondoliers ascend to the monarchy, and pirates emerge as noblemen who have gone astray. Sullivan, six years Gilbert's junior, composed the music, contributing memorable melodies that could convey both humour and pathos.
Context: Sullivan was born in London on 13 May 1842. His father was a military bandmaster, and by the time Arthur had reached the age of eight, he was proficient with all the instruments in the band. In school he began to compose anthems and songs. In 1856, he received the first Mendelssohn Scholarship and studied at the Royal Academy of Music and then at Leipzig, where he also took up conducting. His graduation piece, completed in 1861, was a suite of incidental music to Shakespeare's The Tempest. Revised and expanded, it was performed at the Crystal Palace in 1862 and was an immediate sensation. He began building a reputation as England's most promising young composer, composing a symphony, a concerto, and several overtures, among them the Overture di Ballo, in 1870.  His early major works for the voice included The Masque at Kenilworth (1864); an oratorio, The Prodigal Son (1869); and a dramatic cantata, On Shore and Sea (1871). He composed a ballet, L'Ile Enchantee (1864) and incidental music for a number of Shakespeare plays. Other early pieces that were praised were his Symphony in E, Concerto for Cello and Orchestra, and Overture in C (In Memoriam) (all three of which premiered in 1866). These commissions, however, were not sufficient to keep Sullivan afloat. He worked as a church organist and composed numerous hymns, popular songs, and parlour ballads.  Sullivan's first foray into comic opera was Cox and Box (1866), written with librettist F. C. Burnand for an informal gathering of friends. Public performance followed, with W. S. Gilbert (then writing dramatic criticism for the magazine Fun) saying that Sullivan's score "is, in many places, of too high a class for the grotesquely absurd plot to which it is wedded." Nonetheless, it proved highly successful, and is still regularly performed today. Sullivan and Burnand's second opera, The Contrabandista (1867) was not as successful.
Question: What was his first success in his career?

Answer:
a suite of incidental music to Shakespeare's The Tempest. Revised and expanded, it was performed at the Crystal Palace in 1862 and was an immediate sensation.