Infanta of Portugal, Maria Anna of Braganza was born on 13 July 1861 at Bronnbach Castle in Wertheim am Main.

The House of Braganza is one of the oldest royal dynasties on the Iberian Peninsula, and her father, the former King Miguel I, reigned over Portugal from 1828 to 1834. Driven from the throne following a civil war between absolutists and liberals, Miguel I lived in exile with his wife, Princess Adelaide of Löwenstein-Wertheim-Rosenberg, who came from a family of German high nobility.

The childhood of Maria Anna and her seven brothers and sisters was marked by the memory of this lost sovereignty and the desire to maintain their princely status. All of them married members of the European aristocracy, thus guaranteeing a wide sphere of influence for the exiled family.

In 1893, the Infanta married Prince William of Luxembourg, heir to the Grand Ducal throne. Their union was initially met with reluctance on the part of Grand Duke Adolphe, William's father, due to the difference in religion between the future spouses: William was raised in the Protestant faith of the House of Nassau, while Maria Anna was a practising Catholic.

However, the fact that Catholicism was the majority religion in Luxembourg, combined with the need to ensure dynastic continuity after Grand Duke Adolphe's accession to the throne in November 1890, led the Grand Duke to give his consent.

Very soon, in June 1894, the couple had their first child, Princess Marie-Adélaïde, who was later followed by five other daughters: Charlotte (1896-1985), Hilda (1897-1979), Antonia (1899-1954), Elisabeth (1901-1950) and finally Sophie (1902-1941). All six princesses were baptised and raised in their mother's Catholic faith.

The Grand Duchess regularly accompanied him abroad, following the recommendations of doctors who hoped that milder climatic conditions would benefit the Grand Duke's health. These treatments proved ineffective and in 1908, the Grand Duke was even forced to appoint Grand Duchess Maria Anna as his representative and then regent the following year.

She then assumed the role of Head of State and administered the affairs of the Grand Duchy with rigour and dedication throughout her husband's incapacity. She held this position until June 1912, when her eldest daughter, Marie-Adélaïde, having reached the age of majority (set at 18), took over as head of the Luxembourg state. Grand Duchess Maria Anna remained at her side during her seven-year reign and retired to Hohenburg Castle in Bavaria upon the accession of her daughter, Grand Duchess Charlotte, in 1919.

Until September 1939, Grand Duchess Maria Anna lived there with her lady-in-waiting, the Countess of Lynar. During the Second World War, following the occupation of Luxembourg by Germany in 1940, she accompanied her daughter Charlotte and the rest of the Grand Ducal family into exile. She settled in New York, where she died on 31 July 1942.

Her remains were repatriated to Luxembourg in 1947 and buried in the Grand Ducal crypt alongside her daughter, Grand Duchess Marie-Adélaïde.

A woman of faith and influence, wife and mother, Grand Duchess Maria Anna played a leading role at a crucial moment in Luxembourg's history, ensuring the continuity of power and the Nassau dynasty by acting as lieutenant-représentant and twice as regent. This exceptional role earned her a lasting place in the country's memory.