Disputes over land ownership became an increasing source of conflict between the crown and the upper nobility and clergy. Land ownership was important because the crown's main source of revenue was taxes from the great estates and tithes from lands owned directly by the king. But in medieval Portugal, hereditary title to land did not exist in any developed legal form. As the original grants of land were obscured by passing years, many of the upper nobility and clergy of the church came to believe that they held their land by hereditary right. Thus, each time a new king ascended the throne, the crown had to review land grants and titles in order to assert its authority and reclaim land removed from the king's patrimony.

The first king to confront this problem was Afonso II, who discovered when he ascended the throne in 1211 that his father, Sancho I, had willed much of the royal patrimony to the church. In 1216, after a lengthy legal battle between the crown and the Holy See over various provisions of Sancho's will, the pope recognized Afonso II's right to maintain the royal patrimony intact. From 1216 until 1221, the Portuguese crown asserted this general right by requiring those who had received donations from previous kings to apply for letters of confirmation. The crown thus created the power to review grants to nobles and ecclesiastical bodies.

The process of confirmation was carried a step further when the king appointed royal commissions authorized to investigate land ownership, especially in the north where much of the feudal land tenure predated the creation of the monarchy. These inquiries, as they were called, gathered evidence from the oldest, most experienced residents in each locale without consulting local nobles or church officials. They revealed a large number of abuses and improper extensions of boundaries, as well as conspiracies to defraud the crown of income. The first inquiry found that the church was the biggest expropriator of royal property. The archbishop of Braga, angered by the activities of the commissions, excommunicated Afonso II in 1219. The king responded by seizing church property and forcing the archbishop to flee Portugal for Rome. In 1220 the pope confirmed the king's excommunication and relieved him of his oath of fealty to the Holy See. This dispute between church and crown ended temporarily when the excommunicated king died in 1223 and his chancellor arranged an ecclesiastical burial in exchange for the return of the seized church property and the promise that future inquiries would respect canon law.

The conflict between the church and crown concerning property was finally resolved during the reign of King Dinis (r.1279-1325). In 1284 Dinis launched a new round of inquiries and in the following year promulgated deamortization laws, which prohibited the church and religious orders from buying property and required that they sell all property purchased since the beginning of his reign. For this action against the church, Dinis, like his father and grandfather, was excommunicated. This time, however, the king refused to pledge 8a4 e obedience to the pope and established once and for all the power of the Portuguese crown to regulate and control the royal patrimony.

This power allowed Dinis to nationalize the most powerful and wealthy of the military-religious orders. The Calatravans, founded in Castile, had in effect become Portuguese when the town of Avis was bestowed upon them by Afonso and they became known as the Order of Avis. In 1288 the Knights of Saint James, also of Castilian origin, became Portuguese when the order elected its own master. In 1312, as the result of an investigation into the activities of the Templars, Pope Clement V suppressed this order and transferred their vast properties in Portugal to the Hospitallers. Dinis was able to prevail upon the pope to give this wealth to a newly founded Portuguese military-religious order called the Order of Christ, which was initially situated at Castro Marim but was later moved to Tomar. After nationalization, most of these orders became chivalric bodies of quasi-celibate landowners. The Order of Avis, however, remained on a war footing and contributed significantly to Portugal's independence from Castile. The Order of Christ also remained a military-religious order, and its wealth was later used by Prince Henry the Navigator to pay for the voyages of discovery.

Data as of January 1993