Ferdinand of Hohenzollern – Sigmaringen was born on 24 August 1865, in the Sigmaringen castle, as the second son of Carol I’s eldest brother, Prince Leopold of Hohenzollern – Sigmaringen, and Princess Antónia of Portugal.

Following the renunciations, first of his father’s,  in 1880, and then of his elder brother’s, Prince Wilhelm of Hohenzollern-Sigmaringen, in 1886, Ferdinand became the heir-presumptive to the throne of his childless uncle, King Carol I of Romania, who would reign until his death in October 1914. In 1889, the Romanian Parliament recognized Ferdinand as prince of Romania.

On 10 January 1893, Prince Ferdinand of Romania married Princess Marie of Edinburgh, daughter of  Prince Alfred, Duke of Edinburgh, and the Grand Duchess Marie Alexandrovna of Russia.

On 10 October 1914, Carol I, died and Ferdinand succeeded him as King of Romania, reigning until his own death on 20 July 1927.

Ferdinand presided over the country’s entry into World War I on the side of the Triple Entente powers against the Central Powers on 27 August 1916.

At the Crown Council held at Cotroceni Palace, King Ferdinand declared: ‘’with tormented soul, I decided to accomplish my duty towards the Romanian people whose destiny I rule’’

Thus he was called the Loyal, respecting his oath when sworn in before the Romanian Parliament in 1914: ’’I will reign as a good Romanian.”

As a consequence of this betrayal toward his German roots, Kaiser Wilhelm II had Ferdinand’s name erased from the Hohenzollern House register in perpetuity.

Despite the setbacks after the entry into war, when Oltenia, Wallachia and Dobruja were occupied by the Central Powers, Romania fought in 1917, at Mărăști, Mărășesti and Oituz and stopped the German advance into Moldavia.

When the Bolsheviks sued for peace in 1918, Romania was surrounded by the Central Powers and forced to conclude the peace. However, Ferdinand refused to sign the treaty. When the Allied forces advanced on the Thessaloniki front, they knocked Bulgaria out of the war, and Ferdinand ordered the re-mobilization of the Romanian Army.  Romania  re-entered the war on the side of the Triple Entente. The outcome of Romania’s war effort was the union of Bessarabia, Bukovina and Transylvania with the Kingdom of Romania in 1918.

On 15 October 1922, at Alba –Iulia, Romania’s symbolical capital, at the “Coronation Cathedral”, especially built for this event, Ferdinand I the Unifier King of all Romanians “from Dniester to Tisza” with the same steel crown used by his uncle, Carol I, for his own coronation. In 1923, a new Constitution, concordantly to post-war realities, was enacted.

On 20 July 1927, Ferdinand the Loyal  passed away in Sinaia,  at the Pelisor castle, at the age of 62, after a long suffering.