He was closely related to Kings Christian VII, Frederick VI and Christian VIII of Denmark through his mother and was a claimant for the Danish throne in the 1860s. Born a prince of the House of Schleswig-Holstein-Sonderburg-Augustenburg and scion of a cadet-line descendant of the Danish royal House of Oldenburg, Christian August was the fiefholder of Augustenborg and Sønderborg. He was also a claimant to the rulership of the provinces of Slesvig and Holstein, and he was also a candidate to become king of Denmark during the succession crisis caused by the childlessness of King Frederick VII of Denmark. He lost the chance to ascend the throne to his distant kinsman, Prince Christian of Schleswig-Holstein-Sonderburg-Beck. Christian August was the eldest son and heir of Frederik Christian II, Duke of Augustenborg and his wife Princess Louise Auguste of Denmark. His father was the head of the senior cadet branch of the ruling house of Denmark, and this the nearest agnatic kin of the kings of Denmark. Furthermore, his mother Louisa Auguste was the daughter of King Christian VII of Denmark, the sister of King Frederick VI and the first cousin of King Christian VIII. Due to all this, Christian August was high in the line of succession to the Danish throne. He also enjoyed additional influence in the Danish court because his sister, Caroline Amalie, was the beloved second wife of King Christian VIII. Christian August's family lost out in the competition for the throne of Denmark mainly because he married a woman deemed unsuitable. As early as 1820, when there was no inkling of any succession crisis, Christian August had married for love a woman of unequal rank and thereby undermined any chance of his being invited to the throne of Denmark.
Biography
In 1848, German-nationalist sympathies prompted a rebellion in Schleswig-Holstein against Danish rule. A provisional government was established at Kiel under the Duke of Augustenborg, who travelled to Berlin to secure the assistance of Prussia in asserting his rights. The First War of Schleswig ensued. However, European powers were united in opposing any dismemberment of Denmark. Among others, Emperor Nicholas I of Russia, speaking with authority as Head of the elder Holstein-Gottorp line, regarded the Duke of Augustenborg a rebel. Russia had guaranteed Schleswig to the Danish crown by the treaties of 1767 and 1773. A treaty of peace between Prussia and Denmark was signed at Berlin on 2 July 1850. Both parties reserved their antecedent rights. Denmark was satisfied that the treaty empowered the king-duke to restore his authority in Holstein with or without the consent of the German Confederation. Augustenborg was ousted from power, as Danish troops marched in to subdue the duchies. The question of the Augustenburg succession made an agreement between the major powers impossible, and on March 31, 1852 the duke of Augustenburg resigned his claim in return for a money payment. Duke Christian sold his rights to the Duchy of Schleswig-Holstein to Denmark in aftermath of Treaty of London, but later renounced his rights to the Duchy of Schleswig-Holstein in favor of his son Frederik August. In 1864, his son Frederick of Augustenborg proclaimed himself rightful Duke of Schleswig and Holstein. Duke Christian August died 1869.
Marriage and issue
Christian married in 1820 his second cousin, Countess Lovisa-Sophie af Danneskjold-Samsøe, a Danish noblewoman who belonged to an illegitimate branch of the Danish royal House of Oldenburg. They had seven children:
Prince Alexander Frederick William Christian Charles Augustus, died young
