1580s, "a scheme or plan in the mind," from Middle French desseign, desseing "purpose, project, design," from the verb in French (see design (v.)). Especially "an intention to act in some particular way," often to do something harmful or illegal (1704); compare designing. Meaning "adoption of means to an end" is from 1660s.
In art, "a drawing, especially an outline," 1630s. The artistic sense was taken into French as dessin from Italian disegno, from disegnare "to mark out," from Latin designare "mark out, devise, choose, designate, appoint" (which is also ultimately the source of the English verb), from de "out" (see de-) + signare "to mark," from signum "identifying mark, sign" (see sign (n.)).
[T]he artistic sense was taken into Fr. and gradually differentiated in spelling, so that in mod.F. dessein is 'purpose, plan', dessin 'design in art'. Eng. on the contrary uses design, conformed to the verb, in both senses. [OED]
General (non-scheming) meaning "a plan our outline" is from 1590s. Meaning "the practical application of artistic principles" is from 1630s. Sense of "artistic details that go to make up an edifice, artistic creation, or decorative work" is from 1640s.