History of (Legal) Ideas

I came across this elegant reflection by Isaiah Berlin about the nature of intellectual history.  From "Russian Intellectual History," an essay collected in The Power of Ideas, 68-69:

What is intellectual history?  It is not a clear and self-explanatory concept.  Such terms as 'political history', 'economic history' and 'social history', however vague their frontiers, however much they may overlap with one another, are not in this sense obscure.  They denote accounts of what certain more or less definable groups of human beings have done and suffered, of the interaction between their members, of the deeds and destinies of those individuals who have been influential in altering the lives of their fellows in certain specific ways, of the interplay between them and external nature or other groups of human beings, of the development of their institutions -- legislative, judicial, administrative, religious, economic, artistic -- and so on . . . . But what is intellectual history?  A history of ideas?  What ideas and conceived by whom? . . . . What is the subject of such speculations and disagreements?  If not the specific ideas that belong to specific disciplines, then what?  General ideas, we shall be told.  What are these?  This is much more difficult to answer . . . .

By 'general ideas' we refer in effect to beliefs, attitudes and mental and emotional habits, some of which are vague and undefined, others of which have become crystallised into religious, legal, or political systems, moral doctrines, social outlooks, psychological dispositions and so forth.  One of the qualities common to such systems and their constituent elements is that, unlike a good many scientific and common-sense propositions, it does not seem possible to test their validity or truth  by means of precisely definable, agreed criteria, or even to show them to be acceptable or unacceptable by means of widely accepted methods.  The most that can be said of them is that they are to be found in that intermediate realm in which we expect to find opinions, general intellectual and moral principles, scales of value and value judgments, mental dispositions and individual social attitudes -- everything that is loosely collected under such descriptions as 'intellectual background', 'climate of opinion', 'social mores', and 'general outlook[.]' . . . . It is this ill-defined but rich realm and its vicissitudes that histories of ideas or 'intellectual histories' supposedly describe, analyse, and explain.

With this stylish, though of necessity imprecise, definition in mind, whom do you think are the leading intellectual historians of law -- not just legal historians, but historians of legal ideas (they may be the same, but they may not be)?