It's easier than ever to access Martti Koskenniemi's scholarship
The indispensable Martti Koskenniemi continues to post more of his backlist on his Academia.edu page. Historians could start with his “History of International Law Histories,” which first appeared in Bardo Fassbender & Anne Peters (eds.), The Oxford Handbook of the History of International Law (Oxford University Press, 2012), 943-971. Another article likely to interest many human rights scholars is his "Expanding Histories of International Law," published last year in the American Journal of Legal History.