In 1282 he married Isabel of Aragon, who would be known as Queen Santa. During 46 years of reign he was one of the main responsible for the creation of the national identity and the rise of the conscience of Portugal as a nation-state: in 1297, after the conclusion of the Reconquest by his father, he defined the frontiers of Portugal in the Treaty of Alcanizes, pursued relevant judicial reforms, instituted the Portuguese language as the official language of the court, created the first Portuguese University and freed the Military Orders in the national territory of foreign influences.
Its centralizing policy was articulated with important economic development actions - such as the creation of countless counties and fairs.
D. Dinis ordered the exploration of the copper, silver, tin and iron mines and also organized its export to other European countries.
In 1308 he signed the first Portuguese trade agreement with England.
In 1312 he founds the Portuguese navy, naming as the 1st Admiral of Portugal, the Genoese Manuel Pessanha.
She was a great lover of arts and letters. Having been a famous troubadour, he cultivated the Cantigas de Amigo, Amor and satire, and contributed to the development of troubadour poetry in the Iberian peninsula. He is thought to have been the first truly Portuguese monarch, having always signed with his full name. Worship and great curiosity of both letters and sciences, he was the great impeller of the translation of many works for Portuguese, among which are the treatises of his grandfather D. Afonso X, the Sage.
D. Dinis, responsible for the creation of the first Portuguese University, initially installed in the area of the current Largo do Carmo in Lisbon and by itself transferred to Coimbra in 1308.
After his death, in 1325 he was succeeded by his legitimate son, Afonso IV of Portugal.