1520s, "request, requisition" (a sense now obsolete), from require + -ment. Meaning "things required, a need, something necessary" is from 1660s. Meaning "that which must be accomplished, necessary condition" is by 1841. Related: Requirements. Fowler points out that requirement "means properly a need" and requisite "a needed thing," though the distinction is a fine one.
That which is required by the nature of the case, or is only indirectly thought of as required by a person, is called a requisite ; that which is viewed as required directly by a person or persons is called a requirement ...; a requisite is more often material than a requirement ; a requisite may be a possession or something that may be viewed as a possession, but a requirement is a thing to be done or learned. [Century Dictionary, 1895]