on January 29th, 1839, five days after Darwin was awarded the great honor of being a member of the Royal Society, Darwin got married in his birthplace of Salopshire. After marriage, Darwin and Emma lived in harmony, and they had 6 men and 4 women, including 1 children. However, none of the children are healthy: two eldest daughters died before they grew up, three daughters and two sons were infertile for life, and the rest of the children were also plagued by illness and mental retardation. Darwin couldn't understand this until he found out in the process of studying plant evolution in his later years that nature hated consanguineous marriage. This just suddenly realized. This is the tragedy of his marriage with his cousin.