Within months of Alexandra's marriage, Dagmar's second older brother, Wilhelm, was elected as King George I of the Hellenes. Her younger sister was Thyra, Duchess of Cumberland. She also had another younger brother, Valdemar. During her upbringing, Dagmar, together with her sister Alexandra, was given swimming lessons by the Swedish pioneer of swimming for women, Nancy Edberg; she would later welcome Edberg to Russia, where she came on royal scholarship to hold swimming lessons for women. The rise of Slavophile ideology in the Russian Empire led Alexander II of Russia to search for a bride for the heir apparent, Tsarevich Nicholas Alexandrovich, in countries other than the German states that had traditionally provided consorts for the tsars. In 1864, Nicholas, or "Nixa" as he was known in his family, went to Denmark where he was betrothed to Dagmar. On 22 April 1865 he died from meningitis. His last wish was that Dagmar would marry his younger brother, the future Alexander III. Dagmar was distraught after her young fiancé's death. She was so heartbroken when she returned to her homeland that her relatives were seriously worried about her health. She had already become emotionally attached to Russia and often thought of the huge, remote country that was to have been her home. The disaster had brought her very close to "Nixa's" parents, and she received a letter from Alexander II in which the Emperor attempted to console her. He told Dagmar in very affectionate terms that he hoped she would still consider herself a member of their family. In June 1866, while on a visit to Copenhagen, the Tsarevich Alexander asked Dagmar for her hand. They had been in her room looking over photographs together. Dagmar left Copenhagen on 1 September 1866. Hans Christian Andersen, who had occasionally been invited to tell stories to Dagmar and her siblings when they were children, was among the crowd which flocked to the quay in order to see her off. The writer remarked in his diary, "Yesterday, at the quay, while passing me by, she stopped and took me by the hand. My eyes were full of tears. What a poor child! Oh Lord, be kind and merciful to her! They say that there is a brilliant court in Saint Petersburg and the tsar's family is nice; still, she heads for an unfamiliar country, where people are different and religion is different and where she will have none of her former acquaintances by her side."