Brian Samuel Epstein (; 19 September 1934 – 27 August 1967) was an English music entrepreneur who managed the Beatles. Epstein first discovered the Beatles in November 1961 during a lunchtime performance at The Cavern Club. He was instantly impressed and saw great potential in the group. Epstein was rejected by nearly all major recording companies in London, until he secured a meeting with George Martin, head of EMI's Parlophone label. In May 1962, Martin agreed to sign the Beatles, partly because of Epstein's conviction that the group would become internationally famous.
The Beatles' early success has been attributed to Epstein's management style, and the band trusted him without hesitation. In addition to handling the Beatles' business affairs, Epstein often stepped in to mediate personal disputes within the group. The Beatles' unquestioning loyalty to Epstein later proved detrimental, as the band rarely read contracts before signing them. Shortly after the song "Please Please Me" rose to the top of the charts in 1963, Epstein advised the creation of Northern Songs, a publishing company that would control the copyrights of all Lennon–McCartney compositions recorded between 1963 and 1973. Music publisher Dick James and his partner Charles Silver owned 51% of the company, Lennon and McCartney each owned 20%, and Epstein owned 9%. By 1969, Lennon and McCartney had lost control of all publishing rights to ATV Music Publishing. Epstein's death in 1967 marked the beginning of the group's dissolution and had a profound effect on each Beatle. In 1997, Paul McCartney said, "If anyone was the Fifth Beatle, it was Brian."