 To the "lex mercatoria" modern English law owes the fundamental principles in the law of partnership, negotiable instruments and trade marks.Sir John Holt (Chief Justice 1689 to 1710) and Lord Mansfield (Chief Justice, 1756 to 1788) were the leading proponents of incorporating the "lex mercatoria" into the common law.Holt did not complete the task, possibly out of his own conservatism (see "Clerke v Martin") and it was Lord Mansfield that became known as the 'founder of the commercial law of this country" (Great Britain).