Portuguese monarchy in the context of "Rex Fidelissimus"

The Kingdom of Portugal was a monarchy in the western Iberian Peninsula and the predecessor of the modern Portuguese Republic. Existing to various extents between the mid-12th century and the early 20th century, it was also known as the Kingdom of Portugal and the Algarves after 1471, and was the main constituent of the United Kingdom of Portugal, Brazil and the Algarves, which existed between 1815 and 1822. It coexisted with the Portuguese Empire, the realm's overseas colonies.

The nucleus of the Portuguese state was the County of Portugal, established in the 9th century as part of the Reconquista by Vímara Peres, a vassal of the King of Asturias. The county became part of the Kingdom of León in 1097, and the Counts of Portugal established themselves as rulers of an independent kingdom in the 12th century, following the Battle of São Mamede. The kingdom was ruled by the Afonsine Dynasty until the 1383–85 Crisis, after which the monarchy passed to the House of Aviz.

The Monastery of the Holy Cross (Portuguese: Mosteiro da Santa Cruz), also known as the Church of the Holy Cross, is a National Monument in Coimbra, Portugal. Because the first two kings of Portugal are buried in the church it was granted the status of National Pantheon.

Founded in 1131 outside the protecting walls of Coimbra, the Monastery of the Holy Cross was the most important monastic house during the early days of the Portuguese monarchy. Saint Theotonius founded this community of Canons Regular of the Holy Cross of Coimbra and served as their first prior. The monastery and church were erected between 1132 and 1223.