How many sons did Niels Bohr have?

Niels Bohr had six sons. They were born to Bohr and his wife, Margrethe Nørlund, during their marriage, which began in 1912.

The family experienced both exceptional achievement and tragedy. Their eldest son, Christian, died in 1934 in a boating accident when he was sixteen. Their youngest son, Harald, died in infancy. The four surviving sons included Hans, Erik, Aage, and Ernest.

Aage Bohr became the most famous of the surviving children in scientific terms. He studied nuclear physics, directed the Niels Bohr Institute, and shared the 1975 Nobel Prize in Physics with Ben Mottelson and James Rainwater for discoveries concerning the collective motion and structure of atomic nuclei.

The number is sometimes misremembered because Aage was the only son to win a Nobel Prize, while another family member, Harald Bohr, became a renowned mathematician—but Harald was Niels Bohr's younger brother, not his son. Niels's brother helped popularize mathematical research in Denmark, whereas the six sons belonged to Bohr's own family with Margrethe.