Tradisi Berkahwin dalam Keluarga dalam Royalti Eropah

Putera Charles dan Camilla berkemungkinan sepupu kedua. Nenek moyang Camilla, Alice Keppel, adalah perempuan simpanan kepada Edward VII dari England, dan bersama-sama mereka melahirkan seorang anak perempuan, Sonia. Camilla, isteri Putera Charles sekarang, ialah cucu perempuan Sonia. Charles dan Camilla adalah sepupu kedua setelah dikeluarkan, jadi mereka adalah hasil perkahwinan sepupu kedua.

Keluarga diraja Sepanyol adalah contoh pembiakan yang baik. Ibu bapa Raja semasa, Juan Carlos dan Sophia dari Greece, kedua-duanya mempunyai masalah dengan pembiakan dalam. Di pihak Juan Carlos, kita melihat sisa-sisa hemofilia yang diturunkan disebabkan oleh perkahwinan campur yang dicatatkan oleh Ratu Victoria. Bapa saudara Juan Carlos, Alfonso dan Gonzalo, kedua-duanya meninggal dunia akibat kekurangan pembekuan darah yang dipercayai disebabkan oleh pembiakan ringan mereka.

Ibu Raja, Sophia, boleh dikatakan mempunyai salah satu kes pembiakan zaman moden yang paling teruk. Dua daripada datuk dan neneknya adalah abang dan kakak, dan apa yang lebih teruk ialah hakikat bahawa datuk dan neneknya juga datuk dan nenek moyangnya kerana keluarga diraja Jerman berkahwin campur.

Putera Philip, suami mendiang Ratu Elizabeth, juga merupakan hasil pembiakan diraja. Putera Philip, seperti Ratu, adalah produk malang perkahwinan campur yang membungkus perkahwinan diraja Eropah pada abad ke-19.

Untuk menyelidiki secara spesifik, datuk nenek ibu Putera Philip ialah Ratu Victoria dari United Kingdom dan Putera Albert dari Saxe-Coburg dan Gotha. Mereka adalah sepupu pertama, berkongsi datuk dan nenek yang sama. Hubungan kekeluargaan yang rapat ini menyerlahkan amalan perkahwinan campur dalam era Victoria dan kesannya terhadap generasi berikutnya.

Additionally, both of Prince Philip's great-grandfathers played roles in perpetuating the pattern of inbreeding. His maternal great-grandfather, King Christian IX of Denmark, was a prominent figure in European royal circles. King Christian's daughter, Princess Alexandra of Denmark, married Queen Victoria's son, Edward VII, further consolidating the interconnections between royal families.

Prince Philip's other great-grandfather was Grand Duke Louis IV of Hesse and by Rhine. He married Queen Victoria's second daughter, Princess Alice, making them Prince Philip's maternal great-grandparents. What makes this connection particularly notable is that Grand Duke Louis IV was the uncle of Prince Philip's paternal great-grandfather, Grand Duke Ludwig III of Hesse and by Rhine. The marriage of Prince Philip's great-grandparents, Princess Alice and Grand Duke Louis IV, effectively made their children both first cousins and second cousins.

Raja dan Ratu Greece, Constantine II dan Anne-Marie dari Denmark, adalah sepupu dua kali, sama seperti Ratu Elizabeth II dan Putera Philip. Mereka berdua adalah keturunan Ratu Victoria dan Raja Christian, ke-9 Denmark. Walau bagaimanapun, tidak seperti Ratu dan Putera England, Raja dan Ratu Greece mempunyai hubungan tiga kali ganda. Mereka berkongsi pekali kekerabatan yang sama, yang bermaksud jumlah pembiakan yang sama.

Empress Napoleon, also known as Mary Louise of Austria, was part of an incredibly inbred family. When Napoleon struggled to provide an heir with his first wife, Josephine, he forced Josephine's daughter to marry his brother. This meant that his stepson was also his brother. However, the most inbred member of the Napoleonic family was Napoleon's second wife, Empress Napoleon. Born as Maria Ludovica Leopoldina Franziska Therese Josepha Lucia, Mary Louise hailed from the House of Habsburg, a family known for its extensive history of intermarriage and consanguinity. In the case of Mary Louise, her parents were double first cousins, intensifying the level of shared ancestry within her immediate family.

Alfonso, the Prince of Spain, was the heir to the Spanish throne in the 1920s, during a highly unstable time in Spanish politics. Like Edward VIII of England, Alfonso renounced his rights to the Spanish throne to marry a commoner. Unfortunately, he passed away in 1938 due to a car accident. His hemophilia, a condition that prevents blood clotting, caused him to bleed to death. Inbreeding within the Spanish royal family played a role in the occurrence of recessive genes inherited by Alfonso. As the great-grandchild of Queen Victoria, who carried hemophilia in her family, Alfonso faced increased risk. The Spanish royal family has a history of marrying close relatives, as mentioned before. Ultimately, Alfonso suffered due to the inbreeding of his ancestors and Queen Victoria's ambition to solidify her reputation as the grandmother of Europe.

Archduchess Gizella of Austria, daughter of Emperor Franz Joseph and Empress Elizabeth, is a lesser-known figure in history. She was the neglected daughter of her parents, who were first cousins. The intense strain caused by their inbreeding affected their children's health. For example, their eldest daughter Sophie died in infancy, likely due to the effects of inbreeding. Another child, Rudolf, suffered from genetic abnormalities and chronic depression, eventually taking his own life. Recent studies have shown a common occurrence of depression within the Habsburg dynasty, suggesting a genetic link. Gizella herself became a figurehead for the consequences of Habsburg inbreeding. She was forced to marry her own cousin at the request of her mother, resulting in physical and emotional suffering for her children. Among her four children, all of them shared eight great-grandparents, who, unfortunately, were not genetically diverse. This situation further compounded the issues caused by inbreeding.

Ludwig II, the Mad King of Bavaria, was a beloved cousin of Empress Elizabeth of Austria. He had a strong appreciation for the arts and commissioned the magnificent Neuschwanstein Castle in the 1800s. However, Ludwig suffered from intense feelings of depression, and his inbreeding is believed to be a significant contributing factor to his mental health struggles. Despite his artistic achievements, Ludwig was eventually dethroned, with his counselors claiming he was insane. Modern studies suggest that Ludwig's depression stemmed from intense guilt over his homosexuality. Nevertheless, inbreeding likely played a role in the intensity of his depression. Interestingly, Ludwig's successor was even more mentally unstable than he was.

Ratu Liliuokalani dari Hawaii, raja terakhir yang memerintah Hawaii, juga mempunyai tahap pembiakan yang tinggi dalam keturunannya. Adalah penting untuk ambil perhatian bahawa terdapat stereotaip malang tentang Hawaii yang mempunyai pembiakan yang berleluasa, yang tidak semestinya benar dalam zaman moden. Walau bagaimanapun, keluarga Liliuokalani mempunyai hubungan darah yang rapat. Datuknya, Ketua Tinggi Kamehameha, adalah datuk moyangnya dua kali kerana kedua-dua datuknya adalah adik-beradik.

King Harald V of Norway holds the distinction of being one of the most inbred royals currently alive. His parents were first cousins, which significantly limited the number of unique great-grandparents he had. While most people have eight unique great-grandparents, Harald only has six. His grandmother and grandfather were not only siblings but also first cousins to each other. Further back in his ancestry, his great-grandmother, who appears twice, was the niece of his great-grandfather. This extensive inbreeding within Harald's lineage makes him the most inbred royal of the present time.