PRINCIPAL OBLIGATION That obligation which arises from the principal object of the engagement which has been contracted between the parties. It differs from an accessory obligation. (q. v.) For example, in the sale of a horse, the principal obligation of the seller is to deliver the horse; the obligation to take care of him till delivered is an accessory engagement. Poth. Obl. n. 182. By principal obligation is also understood tho engagement of one who becomes bound for himself and not for the benefit of another. Poth. Obl. n. 186.