Charlemagne: 
King of the Franks and emperor of the Romans in the late eight and early ninth centuries, Charlemagne had 20 children, some with wives and others with concubines. He insisted that they all receive a thorough education, including the girls. When one of his sons, known as Pepin the Hunchback, was found guilty of participating in a plot to kill Charlemagne, it was expected that he would be executed along with his co-conspirators. Instead, the emperor took pity on Pepin, ordered his sentence commuted and sent him to a monastery.

Czar Nicholas II: 
The last Russian emperor, Nicholas had five children with his wife, the German-born Alix of Hesse. A loving father, Nicholas was especially concerned with the health of his only son and heir, Alexei, who suffered from hemophilia. Their child’s illness led the czar and his wife to consult the controversial healer Rasputin, whose influence over the royal family compromised their standing on the eve of the Russian revolution.

Mark Twain: 
Mark Twain and his wife, Olivia, had three daughters during their 34-year marriage. Though he doted on all his children, Twain was particularly close with his oldest, Susy, who shared his love of acting and writing. He based at least two major characters in his novels on her. When she died of meningitis as a young woman in 1896, Twain fell into a deep depression. Later, he included passages written by Susy about her father in his autobiography.

Cicero: 
A prominent ancient Roman statesman and philosopher, Cicero adored his daughter Tullia and was devastated when she died of complications from childbirth in 45 B.C. Inconsolable despite his friends’ many letters of condolence, some of which are still in existence, Cicero isolated himself for several weeks at the home of his friend Atticus, where he read texts by Greek philosophers about how to overcome grief. He later divorced his second wife, Pubilia, supposedly because she had not been sufficiently saddened by her stepdaughter’s death.

Charles Darwin
: The father of modern evolutionary science was also a devoted dad to 10 children, of whom two died in infancy. He played a central role in raising and educating his brood at a time when childrearing was seen as women’s work. The death in 1851 of 10-year-old Annie was a crushing blow for Darwin and his wife, Emma, and some have speculated that it caused him to lose his religious faith.