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, 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 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.

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.

Strictly speaking the Pact of Dover and the Pact of Paris were private agreements, legally unenforceable.
 Nor did King Manuel agree to any provision in the latter pact which contravened Portugal's last monarchist constitution.
 But the agreements were important steps in reconciling the Miguelist and the Braganza-Saxe-Coburg branches of Portugal's royal family, and helped move the supporters of each toward a united monarchist movement.

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 Amelie.

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".

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 Emperor Franz Josef I of Austria 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 su
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, 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 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.
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.
Strictly speaking the Pact of Dover and the Pact of Paris were private agreements, legally unenforceable.  Nor did King Manuel agree to any provision in the latter pact which contravened Portugal's last monarchist constitution.  But the agreements were important steps in reconciling the Miguelist and the Braganza-Saxe-Coburg branches of Portugal's royal family, and helped move the supporters of each toward a united monarchist movement.
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 Amelie.
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".
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 Emperor Franz Josef I of Austria 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 su
Duarte Nuno, Duke of Braganza