Fritz Pfeffer was born on April 30 1889 in Giessen, Germany. He was given the rather unflattering name Albert Dussel by Anne, which translates as 'idiot.'
Fritz (Albert) was a dentist in Berlin and married Vera Bythiner in 1921. They had one son together called Werner. The marriage ended in divorce in 1933 and Fritz gained custody of Werner.
He then met Charlotte Kaletta, a Catholic, who was also divorced with a son. Due to the Nürnberg Laws which prevented Jews and non-Jews from marrying, it was impossible for them to wed. Following increased violence against Jews in Germany in 1938, Werner was sent to England as a refugee and Fritz and Charlotte fled to Holland.
Fritz was Miep's dentist and when it became clear that it was no longer safe in Nazi-occupied Holland, he asked her if she knew of a safe hiding place. Fritz joined the other occupants of the Secret Annex on 16 November 1942.
Although Anne was initially positive that someone else had joined the Secret Annex, she was made to share her bedroom with Fritz - something which caused her annoyance, particularly having to share her writing desk.
Miep acted as a courier between Fritz and Charlotte during his time in hiding - they would send letters and packages to each other, but Miep never revealed to Charlotte that she knew where Fritz was.
In August 1944, Fritz was arrested when the Secret Annex was raided by the security police. He was transferred with the others to Westerbork camp and on to Auschwitz-Birkenau.
From here he was deported to Neuengamme concentration camp near Hamburg and died on 20 December 1944.
Charlotte Kaletta married Fritz Pfeffer posthumously on 9 April 1953. His son, Werner, survived the war in England and emigrated to the United States in 1947.
Nicholas's film credits include Chariots of Fire, Greystoke: The Legend of Tarzan, Lord of the Apes and The Jewel in the Crown. He also starred in a television adaptation of Mansfield Park and has appeared in Waking the Dead, Casualty 1907 and Criminal Justice.
"Albert's portrait in the diary is one of the least flattering. The diary on one level works as a study of what happens if we shut up ordinary people together in a small space for too long.
"If a 13-year-old girl is suddenly forced to share her small bedroom with a 54 year old stranger, a lot of tension is sure to ensue, and Anne's version of the man reflects that. But there is another side to Mr Dussel.
"He had, after all, the foresight to send his son to London in 1938. He was deeply in love with a Catholic girl, and felt the pain of the enforced separation deeply."
BBC © 2014 The BBC is not responsible for the content of external sites. Read more.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.