Charles was born on 17 August 1887, in the Castle of Persenbeug, in Lower Austria. His parents were Archduke Otto Franz of Austria and Princess Maria Josepha of Saxony. At the time, his great-uncle Franz Joseph reigned as Emperor of Austria and King of Hungary. Upon the death of Crown Prince Rudolph in 1889, the Emperor’s brother, Archduke Karl Ludwig, was next in line to the Austro-Hungarian throne. However, his death in 1896 from typhoid made his eldest son, Archduke Franz Ferdinand, the new heir presumptive.

It was during one of these visits that Charles and Zita became reacquainted. Due to Franz Ferdinand’s morganatic marriage in 1900, his children were excluded from the succession. As a result, the Emperor pressured Charles to marry. Zita not only shared Charles’ devout Catholicism, but also an impeccable royal lineage. Zita later recalled:

In 1907, he was declared of age, and Prince Zdenko Lobkowitz was appointed as his chamberlain. During the next few years, he carried out his military duties in various Bohemian garrison towns. Charles’ relations with his great-uncle were not intimate, and those with his uncle Franz Ferdinand were not cordial, with the differences between their wives increasing the existing tension between them. For these reasons, Charles, up to the time of the assassination of his uncle in 1914, obtained no insight into affairs of state, but led the life of a prince not destined for a high political position.

In 1911, Charles married Princess Zita of Bourbon-Parma. They had met as children but did not see one another for almost ten years, as each pursued their education. In 1909, his Dragoon regiment was stationed at Brandýs nad Labem in Bohemia, from where he visited his aunt at Franzensbad.

Archduke Charles traveled to Villa Pianore, the Italian winter residence of Zita’s parents, and asked for her hand; on 13 June 1911, their engagement was announced at the Austrian court. Charles and Zita were married at the Bourbon-Parma castle of Schwarzau in Austria on 21 October 1911. Charles’s great-uncle, the 81-year-old Emperor Franz Joseph, attended the wedding. He was relieved to see an heir make a suitable marriage, and was in good spirits, even leading the toast at the wedding breakfast. Archduchess Zita soon conceived a son, and Otto was born 20 November 1912. Seven more children followed in the next decade.

Charles became heir presumptive after the assassination of Archduke Franz Ferdinand in Sarajevo in 1914, the event which precipitated World War I. Only at this time did the old Emperor take steps to initiate the heir-presumptive to his crown in affairs of state. But the outbreak of World War I interfered with this political education. Charles spent his time during the first phase of the war at headquarters at Teschen, but exercised no military influence.

Charles succeeded to the thrones in November 1916 after the death of his grand-uncle, Emperor Franz Joseph. On 2 December 1916, he assumed the title of Supreme Commander of the whole army, succeeding Archduke Friedrich. His coronation as King of Hungary occurred on 30 December. In 1917, Charles secretly entered into peace negotiations with France. He employed his brother-in-law, Prince Sixtus of Bourbon-Parma, an officer in the Belgian Army, as intermediary. However, the Allies insisted on Austrian recognition of Italian claims to territory and Charles refused, so no progress was made. Foreign minister Graf Czernin was only interested in negotiating a general peace which would include Germany, Charles himself went much further in suggesting his willingness to make a separate peace. When news of the overture leaked in April 1918, Charles denied involvement until French Prime Minister Georges Clemenceau published letters signed by him. This led to Czernin’s resignation, forcing Austria-Hungary into an even more dependent position with respect to its seemingly wronged German ally.

From the beginning of his reign, Karl favored the creation of a third Croatian political entity in the Empire, in addition to Austria and Hungary. In his Croatian coronation oath in 1916, he recognized the union of the Triune Kingdom of Croatia, Dalmatia and Slavonia with Rijeka and during his short reign supported trialist suggestions from the Croatian Sabor and Ban, but the suggestions were always vetoed by the Hungarian side which did not want to share power with other nations. After Emperor Karl’s manifesto of 14 October 1918 was rejected by the declaration of the National Council in Zagreb. President of the Croatian pro-monarchy political party Pure Party of Rights Dr. Aleksandar Horvat, with other parliament members and generals went to visit the emperor on 21 October 1918 in Bad Ischl, where the emperor agreed and signed the trialist manifesto under the proposed terms set by the delegation, on the condition that the Hungarian part does the same since he swore an oath on the integrity of the Hungarian crown. The delegation went the next day to Budapest where it presented the manifesto to Hungarian officials and Council of Ministers who signed the manifesto and released the king from his oath, creating a third Croatian political entity (Zvonimir’s kingdom). After the signing, two parades were held in Zagreb, one for the ending of the K.u.K. monarchy, which was held in front of the Croatian National Theater, and another one for saving the trialist monarchy. The last vote for the support of the trialist reorganization of the empire was, however, too late. On 29 October 1918, the Croatian Sabor (parliament) ended the union and all ties with Hungary and Austria, proclaimed the unification of all Croatian lands and entered the State of Slovenes, Croats and Serbs. The curiosity is that no act of Sabor dethroned King Karl IV, nor did it acknowledge the entering in a state union with Serbia, which is today mentioned in the preamble of the Constitution of Croatia.

Encouraged by Hungarian royalists (“legitimists”), Charles sought twice in 1921 to reclaim the throne of Hungary, but failed largely because Hungary’s regent, Admiral Miklós Horthy (the last commander of the Imperial and Royal Navy), refused to support Charles’ restoration. Horthy’s action was declared “treasonous” by royalists. Critics suggest that Horthy’s actions were more firmly grounded in political reality than those of Charles and his supporters. Indeed, neighbouring countries had threatened to invade Hungary if Charles tried to regain the throne. Later in 1921, the Hungarian parliament formally nullified the Pragmatic Sanction, an act that effectively dethroned the Habsburgs.

After the second failed attempt at restoration in Hungary, Charles and his pregnant wife Zita were arrested and quarantined at Tihany Abbey. On 1 November 1921 they were taken to the Hungarian Danube harbour city of Baja, were taken on board the monitor HMS Glowworm, and there removed to the Black Sea where they were transferred to the light cruiser HMS Cardiff. On 19 November 1921 they arrived at their final exile, the Portuguese island of Madeira. Determined to prevent a third restoration attempt, the Council of Allied Powers had agreed on Madeira because it was isolated in the Atlantic Ocean and easily guarded.

The couple and their children, who joined them on 2 February 1922, lived first at Funchal at the Villa Vittoria, next to Reid’s Hotel, and later moved to Quinta do Monte. Compared to the imperial glory in Vienna and even at Eckartsau, conditions there were certainly impoverished.

Charles did not leave Madeira. On 9 March 1922 he had caught a cold in town, which developed into bronchitis and subsequently progressed to severe pneumonia. Having suffered two heart attacks, he died of respiratory failure on 1 April, in the presence of his wife (who was pregnant with their eighth child) and nine-year-old former Crown Prince Otto, remaining conscious almost until his last moments. His last words to his wife were “I love you so much.” His remains except for his heart are still on the island, resting in state in a chapel devoted to the Emperor in the Church of Our Lady of The Hill (Igreja de Nossa Senhora do Monte), in spite of several attempts to move them to the Habsburg Crypt in Vienna. His heart and the heart of his wife are entombed in Muri Abbey, Switzerland.

The cause or campaign for his canonization began in 1949, when the testimony of his holiness was collected in the Archdiocese of Vienna. In 1954, the cause was opened and he was declared “servant of God”, the first step in the process. At the beginning of the cause for canonization in 1972 his tomb was opened and his body was discovered to be incorrupt.

Pope John Paul II declared Charles “Blessed” in a beatification ceremony held on 3 October 2004, and stated: