In the Bodleian Law Library, comparative & general (ie not single country specific) commentary on this topic have shelf marks beginning either Legal Hist or Cw Gen or General. All three collections are shelved on Level 2, the entrance level of the Law Library a few paces away from each other. Please ask at the Enquiry Desk (also on this floor) if you are having any difficulty locating them.
There are two general subject searches to use in SOLO
Law -- Great Britain -- Colonies -- History;
Law -- Commonwealth countries -- History
Or look for works on single jurisdictions by constructing subject searches following example below:
Law -- Australia - History
Also on level 2 is A bibliography of the law of British colonies, protectorates and mandated territories : being volume VII of Sweet &Maxwell's legal bibliography at Ref Bibl Cw UK M464/7. NB This was published in 1949, but can still be useful in identifying older works.
Open access available to all with access to the internet
The following jurisdiction guides have a page looking at the nation's legal history: