Legal system and administration of justice
The administration of justice in the principality was exercised by the local administrative authorities. Under the Villehardouins the disputes among the nobles were settled by the "big court", in which participated the prince and the vassals of the dependent regions, such as the barons and the duke of Athens, Naxos, Euboea, Bodonitsa and Cephalonia. Inside each barony the "small court" had the jurisdiction to determine issues concerning the vassals of the barony.
The Assizes of Romania was the feudal code of the Peloponnese consisting of 219 clauses, which determined the legal relations between the paroikoi (serfs) and the lords, as well as the obligations of the vassals and the prince. The full title was Liber Consuetudinum imperii Romaniae and were first published in 1785 by Paolo Canciani in Barbarorum leges antiquae cum notis et glossariis. The official codification was carried through by the Venetians in 1453 and was based on previous texts of the 13th century and on oral tradition. The compilation of the Assizes raises questions, as to whether they had been influenced by the Assizes of Jerusalem (a code compiled by Geoffrey de Bouillon in 1099) or developed at the same time but without influencing one another.
A typical example of the enforcement of the Assizes in the principality, during the 13th century, and of the registration of certain articles (book) is the trial of Margaret de Passava in 1276, a detailed description of which is found in the Chronicle of the Morea, ver. 7301-7752 and which provides information about the feudal law. More specifically, Margaret, daughter of Jean de Neuilly the baron of Passava (marshal of the principality) had been sent as a hostage (opsida) to Constantinople, in order to free the prince William II de Villehardouin, who had been captive for three years after the battle of Pelagonia in 1259. During her captivity, her uncle Gautier de Rosieres, baron of Akova, died in 1273 and Margaret was his only heir. When she returned, she claimed the barony of her uncle, but the prince said that she had no right on it, seeing that the specified period (termena) had elapsed.
According to art. 36 of the Assizes, heritage should be claimed within 40 days, if the feudal lord was in the principality, otherwise the annual revenues were lost. On the other hand, if the heir did not appear for a year and one day or two years and two days, in case he was not in the principality, the property returned to the prince. Margaret opposed to that, because the reason for which she did not claim the heritage in time was lawful and justified. The court that was convened ruled that Margaret was not entitled to the heritage, seeing that the legal time limit had elapsed, whereas as a vassal she had the obligation to serve the prince (as a captive, Assizes art. 15, 17). As an act of generosity, prince William II granted her 1/3 of the barony of Akova as "neo doma" (ver. 7692) and gave the remaining 2/3 to his second daughter Margaret as "goniko" (ver. 7748).