By far the most important source is the Digest.
There is an English translation by a team of scholars headed by Alan Watson; it comes as a stand-alone edition with a facing
Latin original. At present there is no online English translation of the entire Digest.
Watson, Alan (ed.) (1998). The Digest of Justinian. Philadelphia: University of Pennsylvania Press. [English]
Watson, Alan (1985). The Digest of Justinian. Philadelphia: University of Pennsylvania Press. [English and Latin]
The titles of the Digest on the major delicts (theft, iniuria, and damnum iniuria datum) are easily accessible in a Penguin edition.
Kolbert, C. (tr.) (1979). The Digest of Roman law: Theft, Rapine, Damage and Insult. New York: Penguin.
There is a very convenient edition of Gaius’s Institutes, in both Latin and English, with notes and a generous outline.
Robinson, O., and Gordon, W. (eds.) (1988). The Institutes of Gaius. Ithaca, N.Y.: Cornell University Press.
There is an edition, translation, and commentary on surviving statute law (of which there is surprisingly little) by another
team.
Crawford, M. (ed.) (1996). Roman Statutes. Bulletin of the Institute of Classical Studies, Supplement 64.
Here I give a brief list of books for further reading. This is hardly a complete bibliography. Rather, it is meant to be a
selection of works that may be useful and reasonably accessible on specific topics. The scholarly literature on Roman law
presents a number of difficulties. Much of it is in foreign languages, and the English-language works often assume a knowledge
of Latin or of modern scholarly languages. Even where there are no language problems, scholars may assume considerable knowledge
of Roman legal detail, prior scholarship on Roman law, or sophisticated concepts of legal studies more generally. One result
of this is that some important topics (e.g., contracts) will not be represented by monographs listed here. In these cases,
however, there are enough general works listed (e.g., those of Borkowski, Johnston, and Nicholas) to provide some guidance.
Alexander, Michael (1990). Trials in the Late Roman Republic, 149 BC to 50 BC. Toronto: University of Toronto Press.
Brief listings for every known trial (civil and criminal) during the period given. Alexander lists the parties involved, the
legal issues, the result, the sources, and other information.
Berger, Adolf (1991). Encyclopedic Dictionary of Roman Law. Philadelphia: American Philosophical Society.
Very handy reference work for the (Latin) terminology of Roman law.
Buckland, W. W. (1969). The Roman Law of Slavery: The Condition of the Slave in Private Law from Augustus to Justinian. New York: AMS Press.
Originally published in 1908, but still a handy compendium on this very important topic.
Borkowski, J. A. (2005). Textbook on Roman Law. Oxford and New York: Oxford University Press.
Crook, J. A. (1967). Law and Life of Rome. London: Thames & Hudson.
A very broad introduction to Roman law with much attention to social context and practical use of the law.
Crook, J. A. (1995). Legal Advocacy in the Roman World. London: Duckworth.
Particularly valuable for bringing together Egyptian documentary evidence for the practice of advocates in day-to-day litigation.
Frier, B. (1985). The Rise of the Roman Jurists: Studies in Cicero’s Pro Caecina (Princeton, N.J.: Princeton University Press.
Written around a particular case of Cicero’s, this book nonetheless looks into much broader issues of the status of jurists
and their evolving role in the Roman legal system.
Frier, B. (1989). A Casebook on the Roman Law of Delict. Atlanta, Ga.: Scholars Press.
Collected texts (mostly drawn from the
Digest) laying out particular cases, with annotation, to explain a variety of concepts of the
law of delict. This is the method by which American law schools generally teach.
——— and McGinn, Thomas (2004). A Casebook on Roman Family Law. Oxford and New York: Oxford University Press.
Like the previous work, but covering family law.
Gardner, Jane F. (1986). Women in Roman Law and Society. London: Croom Helm.
Gardner, Jane F. (1998). Family and Familia in Roman Law and Life. New York: Clarendon Press.
These works focus on adoption, emancipation, and the relationship between mothers and their children.
Grubbs, Judith Evans (1995). Law and Family in Late Antiquity: The Emperor Constantine’s Marriage Legislation. Oxford and New York: Clarendon Press, Oxford University Press.
Grubbs, Judith Evans (2002). Women and the Law in the Roman Empire: A Sourcebook on Marriage, Divorce and Widowhood. London and New York: Routledge.
Johnston, David (1988). The Roman Law of Trusts. Oxford: Clarendon Press.
The history and use of trusts (fideicommissa) in the law of inheritance.
Johnston, David (1999). Roman Law in Context. Cambridge and New York: Cambridge University Press.
A general introduction to Roman private law, with a special focus on its practical business applications.
Nicholas, Barry (1962). An Introduction to Roman Law. Oxford: Clarendon Press.
General introduction to Roman law from a modern lawyer’s point of view.
Nippel, Wilfried (1995). Public Order in Ancient Rome. Cambridge and New York: Cambridge University Press.
Policing and other means to maintain public order.
Riggsby, Andrew M. (1999). Crime and Community in Ciceronian Rome. Austin, Tex.: University of Texas Press.
The procedures and offenses covered by the criminal courts of the late Republic.
Robinson, O. F. (1997). The Sources of Roman Law: Problems and Methods for Ancient Historians. London and New York: Routledge.
Detailed but readable account of both the sources for and sources of Roman law treated in
Chapters 4 and
5 of this book.
Saller, Richard P. (1994). Patriarchy, Property, and Death in the Roman Family. Cambridge and New York: Cambridge University Press.
Sets out the legal rules for paternal authority in cultural and demographic context.
Tellegen-Couperus, O. E. (1993). A Short History of Roman Law. London and New York: Routledge.
A history not so much of the law as of legal (and related political) institutions.
Watson, Alan (1995). The Spirit of Roman Law. Athens: University of Georgia Press.
Watson has written an enormous quantity of very technical works on all areas of the law, but this is a very basic account
of his theories on the general production and interpretation of the law.