Modistic syntactic theory represents in large part the continued development of earlier ideas. Its background begins with the late Roman grammarians who wrote down descriptions of the classical Latin language for posterity – writers such as Donatus, Charisius, Diomedes, and Servius in the fourth century, Phocas and Pompeius in the fifth, and Priscian in the early sixth. The grammarians of the Carolingian Renaissance, such as Alcuin of York (fl. 781-96), Sedulius Scottus (fl. 848-58), and Remigius of Auxerre (c. 900), made use of the writings of many of their Roman predecessors and kept essentially the same descriptive framework.

By the eleventh or twelfth century, however, the range of Roman grammarians whose works were used in the schools of northern Europe had narrowed to two: Donatus and Priscian. The Ars grammatica of Donatus – the first part of which, the Ars minor, is phrased in a catechism-like question-and-answer format – says nothing significant about syntax. The only substantial Roman source for medieval syntactic theory is therefore Priscian, whose eighteen-book Institutiones grammaticae constitute the most voluminous, most thorough, and most disorganized of the surviving Roman grammars. The first sixteen books, referred to in the Middle Ages as Priscianus maior, discuss the individual parts of speech, and the last two (Priscianus minor) are explicitly devoted to syntax, though syntactic information is scattered through the other books as well.