Fritz Pfeffer Friedrich " Fritz " Pfeffer ( 30 April 1889 – 20 December 1944 ) was a German dentist and Jewish refugee who hid with Anne Frank during the Nazi Occupation of the Netherlands , and who perished in the Neuengamme concentration camp in Northern Germany . Pfeffer was given the pseudonym Albert Dussel in Anne ' s diary , and remains known as such in many editions and adaptations of the publication . Early life . Fritz was born in Gießen , Germany , one of the five children of Ignatz Pfeffer and Jeannette Hirsch - Pfeffer , who lived above their clothing and textiles shop at 6 Marktplatz in Giessen . After completing his education , Fritz trained as a dentist and jaw surgeon , obtained a license to practice in 1911 and opened a surgery the following year in Berlin . He served in the German Army during the First World War and afterwards , in 1921 married Vera Bythiner ( 31 March 1904 – 30 September 1942 ) , who was born in Posen in Imperial Germany ( now Poznań , Poland ) . The marriage produced a son , Werner Peter Pfeffer ( 3 April 1927 – 14 February 1995 ) , then the couple divorced in 1932 . Fritz was granted custody of the boy and raised him alone until November 1938 , when the rising tide of Nazi activity in Germany persuaded him to send him into the care of his brother Ernst in England . Werner emigrated to California in 1945 after his uncle ' s death and changed his name to Peter Pepper , later establishing a successful office supplies company under that name . The tide of antisemitism in Germany , which increased from the election of Adolf Hitler in 1933 , forced most of Fritz ' s relatives to flee the country . His mother had died in 1925 ; his father remarried and remained in Germany , only to be arrested ; he died in Theresienstadt in October 1942 . His elder brother Julius Pfeffer had died in 1928 , Emil Pfeffer emigrated to South Africa in 1937 , Ernst Pfeffer moved to England and died in 1944 , and Hans left for New Jersey . Their sister Minna remained with their father in Germany and died in Nazi custody . Vera escaped to Holland but was arrested in 1942 and died in Auschwitz . In 1936 he met a young woman Charlotta Kaletta ( 1910 – 1985 ) , born in Ilmenau , Thuringia in Central Germany , who shared his history of a broken marriage . She was estranged from her first husband , Ludwig Lowenstein , and their son Gustaf . ( Photos of Ludwig Lowenstein and his son , Gustav , can be found on the Yad Vashem website . ) The couple moved in together but were prohibited from marrying under the 1935 Nazi Nuremberg Laws which forbade marriages between Jews and non - Jews . Kristallnacht cemented their decision to leave Berlin and they fled to Amsterdam in December 1938 . They were there for two years before the German invasion , and subsequent anti - Jewish laws which did not permit the co - habitation of Jews and non - Jews , forced them to officially separate and register under different addresses . After establishing a dental practice in Amsterdam ' s Rivierenbuurt he became acquainted with the Van Pels and Frank families . Miep Gies met Pfeffer at one of the Franks ' house parties and became a patient in his dental practice . In hiding and afterwards . In the autumn of 1942 , he decided to go into hiding and asked Miep Gies about suitable addresses . She consulted Otto Frank , who , with his and the van Pels family , was being hidden by her in secret rooms in the Franks ' office building . Frank agreed to accommodate Pfeffer , and he was taken into their hiding place on 16 November , where his medical degree came in handy as they could not contact a doctor while in hiding . Margot Frank moved into a room with her parents , to allow Pfeffer to share a small room with Anne , beginning what would become a torturous relationship for both . It has been suggested by at least one biographer that Anne ' s extreme discomfort at sharing her room with a middle aged man while she was going through puberty may have been at the root of her problems with Pfeffer , but the pressures of being in hiding and the generational differences of their forty - year age gap undoubtedly exacerbated the differences in their natures . Pfeffer felt his age gave him seniority over Anne and wrote off her writing activities as unimportant compared to his own studies . His observance of orthodox Judaism clashed with her liberal views . Her energy and capriciousness grated on his nerves , while his pedantry and rigidity frustrated her . Anne ' s irritations and growing dislike of Pfeffer led to complaints and derisory descriptions of him in her diary , against which his son Werner and wife Charlotta defended him once the book was published . Pfeffer left a farewell note to Charlotta and they stayed in touch through Miep , who met her on a weekly basis to exchange their letters and take provisions from her . His letters never disclosed the location of his hiding place and Miep never revealed it , but on 4 August 1944 Pfeffer and the seven other occupants of the hiding place were anonymously betrayed and arrested for deportation to Nazi concentration camps . With the rest of the group and two of their protectors , Johannes Kleiman and Victor Kugler , Pfeffer was taken to the Nazi headquarters in Amsterdam - South , then to a prison for three days before being transported to Westerbork on 8 August . Pfeffer was taken to the Punishment Barracks with the others , where he undertook hard labour , until he was selected for deportation to Auschwitz on 3 September . He was separated from the others on arrival on 6 September and sent to the men ' s barracks , where he was reunited with Otto Frank . On 29 October he was transferred with 59 other medics to Sachsenhausen and from there to Neuengamme on an unknown date . There , he died at age 55 in the sick barracks , of enterocolitis on 20 December 1944 , according to the camp ' s records . Posthumous reputation . According to the research done by Melissa Müller for her book " Anne Frank - The Biography " , Charlotta married Pfeffer posthumously in 1950 , with retrospective effect to 31 May 1937 . She had become estranged from his son Werner but both were united in their defense of Pfeffer after the publication of Anne Frank ' s diary in 1947 , feeling that Anne ' s portrait of him — and of the pseudonym she had chosen for him , Mr . Dussel , which in German is " Mr . Nitwit " — was injurious to his memory . Otto Frank tried to placate them by reminding them of Anne ' s youth and of the unflattering portraits of some of the other people in hiding . The subsequent exaggerations of this portrait in the 1955 play and 1959 movie ( in which he was played by comic actor Ed Wynn ) led Charlotta to contact the screenwriters Albert Hackett and his wife Frances Goodrich to complain that they were libelling her deceased husband , who was depicted as ignorant about Jewish traditions . The Hacketts replied that their script did not mirror reality and that to inform a non - Jewish audience of the significance of Judaic ceremonies one character had to be ignorant of them . Charlotta pointed out that her husband was far from unbelieving and a master of Hebrew , but the character of " Mr . Dussel " remained unchanged . Embittered by the unrepresentative portrait , she severed her links with Otto Frank and Miep Gies as Anne ' s fame grew in the decades after the war , and refused requests to be interviewed about her memories of him . Werner remained in touch with Otto and had the opportunity to meet Miep shortly before he died of cancer in 1995 , to thank her for her attempt to save his father ' s life . The meeting between Miep and Werner was recorded for the documentary film " Anne Frank Remembered " . A collection of letters written by Pfeffer to Charlotta and a box of photographs of him were rescued , with some of Charlotta ' s possessions , from an Amsterdam fleamarket after her death in 1985 . Ed Wynn ' s portrayal of Pfeffer ( as Dussell ) in George Stevens ' 1959 film " The Diary of Anne Frank " earned him an Oscar nomination .