Abstract: This Article is the fourth in a four-part series entitled Legal Ideology and Incorporation. In this series, Dean Coquillette demonstrates that, although England has fostered a strong common law system, significant intellectual work was done in England during the sixteenth and seventeenth centuries by students of the civil law systems dominant on the Continent, particularly in their mercantile and diplomatic specialties. Dean Coquillette traces the development of the juristic works of these English civilians, and examines the civilians' intellectual influence on the English common law. It is his central thesis that the English civilian jurists never intended to achieve a direct "incorporation" of civil law or mercantile doctrines into the common law. Rather, their lasting achievement has been the significant influence that their ideas about law - their "legal ideology" - have exercised on leading common lawyers and on modem commercial and international law.