To understand the survival of the Corpus Iuris Civilis, it is worth understanding the status that Roman law held in its own time and what kind of documents constituted it. The Corpus was an enormous legal project: an attempt to distil all previous juristic knowledge into a single body of work (the Digest), to compile all effective enactments of the Emperor into two volumes (the Codex), and to set up a system of legal education which teach future legal practitioners how to wield this material (the Institutes). The Corpus Iuris Civilis was not innovative in its effort to condense existing legal material, for there were precursors to the Digest and the Codex (such as the Codex Gregorianus, the Codex Hermogenianus, and the Codex Theodosianus). Nor was there too much difficulty in getting one's hands on compendiums of the material that constituted the Corpus, for such texts were produced throughout the empire.
However, it was novel as an attempt to simultaneously condense, standardise, and centralise the law. An example of the centralising principles that ran in the background of the effort is the mandated use of the Law of Citations. This law declared that judges working with juristic material had to side with the majority of opinion among five jurists: Papinian, Paul, Gaius, Ulpian, and Modestinus. If there was no majority opinion amongst these, the judge had to rule with Papinian. So judges were no longer to have discretion in the use of legal material. Indeed, all juristic work besides the excerpts in the Digest was deemed inadmissible in court. What we're seeing here is an effort by Justinian to bring all legal proceeding in line with the body of law that his top jurists, led by Tribonian, decided was good.
But the effort to standardise legal procedure was not entirely successful. Competing social pressures determined the Justinianic system's power and have obscured the story of the Codex's survival. The historian Paul Vinogradoff has called the Codex's odyssey through the early medieval period a “ghost story”. I want to bring light on two important points before turning to the reasons why the Corpus was revived in eleventh-century Europe.
Firstly, we know from the Constitutio Antoniniana, which gave all freemen in Rome citizenship, that access to Roman law did not necessarily entail its use. Because the Roman legal system did not have territorial jurisdiction like modern legal systems, but rather could be invoked only on the basis of one's personal status, the Constitutio Antoniniana is a turning point in ease of access to the law. However, as Caroline Humfrees as written: “Even if we were to suppose that individuals had unlimited access to relevant jurisprudential texts and legal expertise (in some cases, a big “if”), we still need to acknowledge what [Chris] Wickham terms “a constant dialectic between local practices and organized legal knowledge.”” To illustrate this point, Humfrees brings up the remains of a Jewish woman – Babatha – which were found to be in possession of legal documents in Greek, Aramaic, and Nabatean. Admittedly, Babatha predates the Constitutio Antoniniana, but she does indicate that forum shopping was a recognised method for navigating between different legal systems in a time when national identities were perhaps not as clean-cut as today. What must be understood is that in the period before the Corpus’ revival, people might be more comfortable using local or 'foreign' legal systems rather than engaging the arms of imperial bureaucracy. In turn, it might be suggested that the Corpus was not revived because of its overwhelming popularity amongst the Byzantines.
On the other hand, the merits of a centralised legal system were respected by rulers besides Justinian, and those rulers respected Justinian’s legal system. One of the most famous indicators of this fact is the Beviary of Alaric, the Visigoths’ mish-mashing of imperial enactments and juristic opinion into a single work. It was created within one generation of the establishment of a full-fledged Visigoth kingdom in the Iberian peninsula and was promulgated to give Romans the choice to use the laws that they preferred whilst on Visigothic soil. Ringing any bells? Another example of such a codex is the Edictum Theodorici, promulgated in Germany for quite the same purpose: to give local Romans the ability to use their own laws.
In conclusion, Roman law had a strange existence up until the eleventh-century. It seems to have been respected as a quality attempt to bring the best of Roman law and juristic opinion into a single place. However, Justinianic law was almost certainly used unevenly by those populations with access to it and there is a sense in which the Visigothic and Germanic legal codes which integrated it did so merely to ensure that ease of access to multiple legal codes was a continued option. This pragmatism with respect to Roman law's reception in the early medieval period led to a slow process of vulgarisation. Snippets of Roman law and procedure survived into Charlemagnian statutes, and Paul du Plessis gives the grim assessment that: “these [codes] at least served the purpose of preserving some elements of the Roman law, and a degree of continuity of legal tradition, however thin”.
The real boom in Roman law occurs in the eleventh century. The documentary survival of Roman law that has been reviewed so far may have been supplemented by the republication of the Digest in Greek in Byzantium, as ordered by Leo VI the Wise. However, it is important to be aware that the two surviving eleventh-century manuscripts for the Digest mutilate the Greek text. It is hard to know whether this indicates that Greek texts were inconsequential to the Digest’s earliest reception in Europe or whether this mutilation existed in the older manuscript on which the two aforementioned texts were based, because the older manuscript is lost.
Importantly, however, that mediating manuscript was inconsequential to the wider restoration of the Digest to scholarly knowledge. That is because the mediating manuscript was based on the Codex Florentinus or Littera Florentina, which was rediscovered in the eleventh-century and was an accurate and contemporary facsimile of the Digest. In short, the original Digest did manage to survive to the eleventh century, supplemented by an enormous wealth of reworked alternatives.
The desire to put the Codex to use, Laurence Mayali has argued, originated in two valuable properties of a centralised legal system. The first function of a revivified law code was that it would be able to control behaviours in the increasingly complicated world of the twelfth- and thirteenth-century Europe. The second function was that people could learn how to think about problems by pouring over the the processes of juristic reasoning that the Digest was witness to. Scholars had a desire to make these laws intelligible and operable and their actual engagement with the material is divided into two major movements.
The first is called the Glossatorial movement. The Glossators were, to put it simply, looking for ways to frame, interpret, and present the huge amount of information that had lately come to their attention. Reproductions of the Digest in its original form continued to be deficient because of linguistic ineptitude – captured by the monastic maxim Graecum est; non legitur – but this did not stop famous scholars like Azo, Accursius, and the Four Doctors from producing enormous works on the Latin matter. A lot of the literature produced in this period were apparatuses (collected glosses of important points of Digest law), summae (extended considerations of a single point of law), and quastiones (notice of conflicting points of law).
The Glossators were committed to stuffy exegetical efforts and thus the value of Roman law remained the jewel of a rather closed circle of scholars. This circle collected in Bologna – the site of the oldest university in Europe – because of the huge success of Irnerius in creating a curriculum that inspired students to become jurists. It would be unfair to call this a completely insular community. Scholars at Bologna often returned home after completing their studies on the peninsula and were therefore partly responsible for the dissemination of Roman law more widely in Europe.
The second, fourteenth-century tradition is that of the Commentators. The Commentators were less committed to explaining the strict letter of the Digest, but rather in making a workable law. The most famous Commentator was Bartolus. In one sense, he simply continued in the older Glossatorial vein, interpreting the Digest where previous scholars had failed to give good readings. However, modern civil law scholars generally appreciate his adept ability to combine Roman law with local customary law. Bartolus used the fact that Roman law was contra bonos mores as sufficient grounds for its invalidation. As Peter Stein argues, this led to his enormous appeal amongst practitioners of the law:
Court advocates and notaries everywhere remained faithful to the Bartolist tradition”. Indeed, “civil law practitioners found much of the humanist scholarship irrelevant to their daily concerns. The arguments that would carry weight with a court were not to be found in humanist discussions of what Ulpian actually meant but in the writings of Bartolus and Baldus… [of which] it was said that it had greater authority than any particular text of the Corpus… itself. This was the ultimate triumph of the commentary over the text in a struggle which had begun with the Glossators.
The Commentators were building on the fact that the Glossators were giving Justinianic law - in something like its original form - the juristic attention that it deserved by recognising that local law was valuable to the reception of a legal system.