"Deep Blue" is a song by English rock musician George Harrison that was released as the B-side to his 1971 charity single "Bangla Desh". Harrison wrote the song in 1970, midway through the recording sessions for All Things Must Pass, and recorded it in Los Angeles the following year while organising the Concert for Bangladesh. The composition was inspired by the deteriorating condition of his mother, Louise, before she succumbed to cancer in July 1970, and by Harrison's feelings of helplessness as he visited her in hospital in the north of England. Given the subject matter, "Deep Blue" also served to convey the suffering endured by the millions of refugees from war-torn Bangladesh in 1971, as sickness and disease became widespread among their makeshift camps in northern India.