Carl Djerassi, the chemist the world calls "the father of the birth control pill", was born 103 years ago today. His mother was from Vienna and his father was a Bulgarian doctor, a Jew from Sofia. He was born in Vienna on 29 October 1923. Read more about Carl Djerassi.

Young Carl spent his first years in Sofia. After his parents divorced, he lived with his mother in Vienna and spent summers with his father in Bulgaria. In 1938 Germany annexed Austria, and the 14-year-old boy from a Jewish family could no longer study safely at his school in Vienna. He moved to Sofia and attended the American College in 1938 and 1939, where he learned good English.

In December 1939 Djerassi left for the United States with his mother. They arrived with almost no money. He turned to chemistry and in 1945, before his 23rd birthday, earned a doctorate in organic chemistry at the University of Wisconsin.

His best-known discovery came in 1951 in Mexico. In the lab of the company Syntex, Djerassi, Luis Miramontes and George Rosenkranz synthesised norethindrone, the first highly active artificial substitute for progesterone that worked as a pill. The body makes the hormone itself, but it breaks down in the stomach and liver, so until then only injections had been possible.

The new molecule became one of the foundations of the contraceptive pill. The pill itself caused long disputes over family, faith and a woman's right to decide for herself when to have children.

From 1960 to 2002, Djerassi was a professor of chemistry at Stanford University. He received the US National Medal of Science in 1973 and the Wolf Prize in 1978. He also wrote novels and plays about science. He died in San Francisco on 30 January 2015, aged 91.