How Christian became the heir
Because of
Salic Law, the succession after childless Frederick was a question very thorny to arrange, and it did not go smoothly, but caused a war. Nationalism pursuing towards independence in the German-speaking parts of
Schleswig-Holstein caused that no solution to keep the Duchies together with Denmark was satisfactory to them and to certain elements in Germany. The
duchies were inherited after the
salic law among descendants of Helwig of Schauenburg, senior of which after Frederick VII was
Frederick, Duke of Schleswig-Holstein-Sonderburg-Augustenburg (1829-1880) (the future father-in-law of
Kaiser Wilhelm II of Germany), who in 1863 proclaimed himself as
Frederick VIII of Schleswig-Holstein. This Friedrich von Augustenburg had become the symbol of the
nationalist German independence-movement in
Schleswig-Holstein, after his father in exchange for money had renounced his claims as
first in line to inherit the twin-duchies of
Schleswig and
Holstein, following the London protocol of
May 8, 1852, which concluded the
First war of Schleswig. Because of his father's renunciation, Frederick was regarded not eligible to succeed by many, such as the Danish-minded.
Denmark was also under Salic Law, but only among descendants of
Frederick III of Denmark (who was the first hereditary monarch of Denmark - before him the kingdom was officially elective). Agnatic descendance of Frederick III went extinct when Frederick VII died, and at that point, the succession law promulgated by Frederick III provided a
Semi-Salic succession. There were however several alternative ways to interpret to whom the crown passes then, since the provision was not entirely clear on whether it be the closest female relative or what and who to inherit. The question was solved by an election and a separate law to confirm the new successor.
The closest female relatives of Frederick VII were the issue of his paternal aunt, Louise, who had married a cadet Landgrave of Hesse. However, they were not agnatic descendants of royal family and thus not eligible to succeed in Schleswig-Holstein.
The dynastic female heiress according to the original primogeniture from Frederick III was
Caroline of Denmark (1793-1881), the childless elder daughter of late king
Frederick VI, after whose childless sister
Wilhelmine of Denmark (1808-1891), Duchess of Glucksburg and sister-in-law of Christian IX, the original primogeniture would have led to heirs of Louise, sister of Frederick VI, who had married the then duke of Augustenburg. The chief heir to that line was the selfsame
Frederick of Augustenborg, but his turn would have come only after the death of two childless princesses who were very much alive in 1863.
Some rights belonged also to the line of Glucksburg, a more junior branch of the royal clan. They were also heirs of Frederick III, through their one ancestress who was daughter of King
Frederick V of Denmark, and they were a more junior agnatic heirs eligible to succeed in Schleswig- Holstein. There were Christian himself and his two elder brothers, eldest of whom was childless, but the second had produced children, also male children.
Prince Christian had been a foster "grandson" of the sonless royal couple Frederick VI and his queen consort Marie (Marie Sophie Frederikke of Hesse), thus familiar with the royal court and the traditions of the recent monarchs. Their young ward, prince Christian was great-nephew of queen Marie, and descendant of a first cousin of Frederick VI. He was brought up as Danish, having lived in Danish-speaking lands of the royal dynasty, and was not attached to German nationalism. Although these did not mean anything legally, they made him a relatively good candidate from the Danish viewpoint. As junior agnatic descendant, he was eligible to inherit Schleswig-Holstein, but not the first in line. As descendant of Frederick III, he was eligible to succeed in Denmark, but not first in line, however that line was not very clear.
Christian married then princess
Louise of Hesse, eldest daughter of the eldest son of the closest female relative of Frederick VII. Louise's father and brothers, princes of Hesse, renounced their rights in favor of Louise and her husband. Prince Christian's wife was now the closest female heiress of Frederick VII.
The thorny question of operation of
Semi-Salic provision in succession of Denmark was at that point resolved by legislation through which Prince Christian of Glücksburg (1818-1906) was 1852 chosen to succeed the King Frederick VII in Denmark.
