Duarte Nuno, Duke of Braganza

In 1974, Duarte Nuno handed over his residence, the Palácio de São Marcos, to the University of Coimbra. From then until his death two years later, he lived in southern Portugal with his unmarried sister, Princess Filippa of Braganza. American author Walter J. P. Curley interviewed Duarte Nuno near the end of his life, and his book Monarchs in Waiting describes Duarte Nuno as suffering from "nervous depression" since the death of his wife in 1968.

Portuguese dictator António de Oliveira Salazar thought about restoring the monarchy in 1951, after the death of President Óscar Carmona, but he chose instead to hold the 1951 Portuguese presidential election and maintain the post of republican Head of State as it had appeared in the Constitution of 1933.

On 27 May 1950 the National Assembly repealed the laws of exile of 19 December 1834 and 15 October 1910. Duarte Nuno, however, did not return to Portugal until 1952 on account of a car accident in Thionville in which he was seriously injured. He was presented with a residence in Portugal by the Fundação Casa de Bragança.

In 1942, the Duarte Nuno married Maria Francisca de Orléans e Bragança, daughter of Pedro de Alcântara, Prince of Grão-Pará. Their marriage reconciled two branches of the House of Braganza, the Portuguese and Brazilian Brigantine houses, and

On 15 October 1942, in the cathedral of Petrópolis in Brazil, Duarte Nuno married Maria Francisca de Orléans e Bragança (8 September 1914 – 15 January 1968), daughter of Pedro de Alcântara, Prince of Grão-Pará. The marriage was particularly popular since Maria Francisca was the great-granddaughter of Pedro II of Brazil, the younger brother of Queen Maria II. The marriage thus united the two rival lines of the Portuguese royal family. Maria Francisca and her family were also viewed as representatives of a liberal monarchy as opposed to the traditional conservatism of Duarte Nuno's family.

Once established in Portugal, the Duke was granted a pension and residence by the Fundação da Casa de Bragança, the organization has owned and managed all the private assets of the House of Braganza, since the death of King Manuel II, in 1932. Duarte Nuno spent the rest of his life attempting, without success, the restoration of all Brigantine assets to his family and recreating the image of the Miguelist Braganzas in Portuguese society, all under the goal of the restoration of the Portuguese monarchy, under the Braganzas.

In 1927, Duarte Nuno's father died. On 2 July 1932 Manuel II died. Henceforth, the majority of monarchists, both Miguelist and constitutional, supported Duarte Nuno as claimant to the Portuguese throne. João António de Azevedo Coutinho, the head of Causa Monárquica and Manuel II's lieutenant while he was in exile, published a declaration in support of Duarte Nuno. Later Duarte Nuno was received in audience in Paris by Manuel's mother, Queen Amélia.

A minority of monarchists considered a candidate other than Duarte Nuno. Manuel's genealogical heir at his death in 1932 was ex-Crown Prince George of Saxony (a great-grandson of Maria II), but he was not Portuguese; he was also a Catholic priest. George's siblings have descendants living, but none is known to have had Portuguese citizenship.

Duarte Nuno's first tutors were two Portuguese ladies, Maria Luisa Castelo and Maria das Dores de Sousa Prego. Later he was taught by the Benedictine monk Frei Estevao from the monastery of Cucujães. Duarte Nuno attended school at the Abbey of Ettal in Bavaria and the Abbey of Clairvaux in France and then completed his secondary education in Regensburg. He received a degree in agricultural sciences from the University of Toulouse. Although forbidden entry to Portugal by the law of exile against the descendants of Miguel I, he visited the country in secret in 1929.

On 17 April 1922 a second agreement called the Pact of Paris was signed by the representatives of Duarte Nuno and Manuel in which Manuel agreed that the Cortes should select his heir if he died without descendants, while Duarte Nuno agreed to ask and recommend that his followers accept Manuel as king-in-exile.

Since Duarte Nuno was only twelve years old when he succeeded as Miguelist claimant to the Portuguese throne, his aunt, the Duchess of Guimarães, acted as regent for him until he attained his majority. In 1921, she issued a manifesto outlining the family's goals for the restoration of the monarchy.

Duarte Nuno's second brother, Prince Francis Joseph of Braganza, died in 1919, and on 21 July 1920 his eldest brother, Prince Miguel, Duke of Viseu, renounced his succession rights. Ten days later on 31 July 1920 Duarte Nuno's father, Miguel Januário, abdicated his claim to the Portuguese throne in favour of Duarte Nuno. Henceforth the Miguelists recognised Duarte Nuno as King Duarte II of Portugal, even though Portugal had become a republic in 1910 when Maria II's great-grandson, King Manuel II (who was still living in 1920), was sent into exile. Duarte Nuno used Duke of Braganza as a title of pretense.

After the death of his uncle Afonso in 1920, ex-King Manuel II had no close relatives who could claim the throne according to the Constitutional Charter of 1826 (the constitution in force from 1842 until the overthrow of the monarchy in 1910). The conflict between the Miguelist line and the Braganza-Saxe-Coburg and Gotha's was not just about which person should be sovereign; it was also about how much power the sovereign should have. The Miguelists upheld Portugal's tradition of autocratic absolutism, while the Braganza-Saxe-Coburg and Gotha's adhered to constitutional monarchy.

In 1912, Duarte Nuno's father, Miguel Januário, met with Manuel to try to come to some agreement so that there would not be two claimants to the Portuguese throne, both living in exile. Their representatives allegedly signed the Pact of Dover by which Miguel Januário recognised Manuel as king, while Manuel recognised the succession rights of Duarte Nuno should Manuel and his uncle Afonso die without children. The pact was unpopular with the supporters of both sides, some claiming that it was never actually signed.

Dom Duarte Nuno, Duke of Braganza (23 September 1907 – 24 December 1976) was the claimant to the defunct Portuguese throne, as both the Miguelist successor of his father, Miguel Januário, Duke of Braganza, and later as the head of the only Brigantine house, after the death of the last ruling Braganza, King Manuel II of Portugal. In 1952, when the Portuguese Laws of Banishment were repealed (27 May 1950), the Duke moved his family to Portugal, thus returning the Miguelist Braganzas to their homeland and becoming the first of the former Portuguese royal dynasty to live in Portugal since the abolition of the monarchy, in 1910.

There was also some doubt about Duarte Nuno's nationality. Duarte Nuno's grandfather had been sent into exile by the law of 19 December 1834. Neither Duarte Nuno nor his father were born in Portugal, but Austrian Emperor Franz Joseph had granted extraterritoriality to Duarte Nuno's birthplace. Article 8 of the 1826 Charter stated that Portuguese citizenship is lost "by those who are banished by sentence". The fact that Duarte Nuno and his father had not been born in Portugal, and the fact that their family had been banished from Portugal left it unclear whether their branch's Portuguese citizenship had been preserved uninterruptedly. However, Dom Duarte's line was banished by law rather than by judicial sentence, and the 1834 constitution in force at the time of D. Miguel I's banishment did not protect the citizenship of those exiled by law. On the other hand, when the Constitutional Charter of 1826 was re-instated in 1842, it cancelled the 1834 charter's clause depriving Miguel I and his heirs of succession rights as dynasts. Their banishment had not, however, been stipulated in that charter, but in a separate law that was not repealed until 1950.

reunited politically the Miguelist and Liberal Braganzas' supporters, which had been estranged since 1828, when the War of Two Brothers was waged between King-Emperor Pedro IV & I, founder of the Liberal Braganzas, and King Miguel I, founder of the Miguelist Braganzas. The couple had three sons, the eldest of whom is Duarte Pio de Bragança, the current pretender to the defunct Portuguese throne.

While Duarte Nuno was accepted by most monarchists, there were some constitutionalists who continued to contest his claim. Duarte Nuno was undisputed as the legal heir of his grandfather, Miguel I, but there were doubts about whether he was the legal heir of the last reigning king of Portugal, Manuel II. Articles 87 and 88 of the Constitutional Charter of 1826, in force when the monarchy was overthrown, stated that the throne passed first to the descendants of Queen Maria II (from whom Duarte Nuno was not descended), and only when they were extinct to collateral heirs. Maria II had living descendants in 1932, but none of these had Portuguese nationality. Article 89 of the 1826 Charter stipulated that "no foreigner may succeed to the crown of the kingdom of Portugal".