In the autumn of 1854, Mauritz Dahlin entered Östersund High School. The town had grown from a village of around 400 inhabitants in 1820 to become much larger during the 1850s as it became a centre for the logging industry. Dahlin spent four years at this school before moving to Uppsala High School in the autumn of 1858. He only spent one school year at Uppsala High School leaving in the spring of 1859. He returned to Uppsala High School in the autumn of 1859 and completed his secondary education there, graduating on 11 June 1867. He did not begin his university studies immediately for it was not until 22 March 1869 that he matriculated at the University of Uppsala. This university, founded in 1477, was the oldest university in Sweden and, at the time that Dahlin studied there, it was one of only two universities in Sweden, the other being Lund University. Dahlin graduated with a Bachelor of Arts degree 13 September 1873 and continued his studies for a Ph.D.
Dahlin undertook research on the history of mathematics for his Ph.D., in particular studying the history of Swedish mathematics. He submitted his thesis Contributions to the history of mathematics in Sweden before 1679 and an oral examination was held on Saturday 22 May 1875 in the Upper Philosophical Lecture Room. His thesis, published in 1875, was dedicated to Carl Fredrik Huss and his wife Eva Catharina Huss:-
With love and gratitude from Mauritz.Carl Fredrik Huss (1811-1897) was a mill owner, foundry proprietor and commissioner of surveyors. An expert businessman, he acquired lands and made a fortune. He was married to Eva Catharina Huss (1821-1900).
Dahlin was awarded the degree on 31 May 1875 and on 8 September of that year he was appointed as a docent in mathematics at Uppsala University. After the award of his Ph.D., Dahlin had been put forward by the Uppsala Faculty of Humanities and Social Sciences for the position of docent in the history of mathematics. However, this was considered was by the chancellor of the university to be too specific a topic for an appointment as docent so his appointment was as a docent in mathematics. However, the authors of  explain that he:-
... hardly possessed any merits that entitled him to an academic teaching position in the mathematical field of research. Dahlin made an, albeit modest, addition to Sweden's history of education with his graduate thesis 'Contributions to the history of mathematics in Sweden before 1679', which mainly consists of concise accounts of Uppsala professors' mathematical papers before the said year. Dahlin points out an important source for the study of history of education, namely the handwritten manuscripts from the astrological observatory in Uppsala (currently deposited in the university library), but one cannot say that he fully made use of this source even with regards to its mathematical content. The thesis does however raise interest by its, at that time, original topic. It can essentially be characterised as a preparatory work for a proper scientific report of the history of mathematics in Sweden before 1679 and retains as such its value, until such report is at hand. Dahlin had started to gather material for a continuation covering the time after 1679, but this work had to be withdrawn, since he for economic reasons was forced to leave the university.(The translation above is from  by Annette Oldsberg.)
Dahlin's thesis was published as a book, see  .
Finding that he could not afford to work as a docent at the university, Dahlin became a bank clerk at Swedish National Bank on 8 April 1876. This position, however, he only had for a few months before he joined the prison service. He was appointed as second teacher at the Langholmen prison on 25 August 1876. He served as Superintendent for Education at Malmö's prisons from 1 February 1877 to 31 December 1878. Although he continued working for the prison service, he took on the additional position as teacher of mathematics at the Department of Mechanical Engineering at Malmö Navigation School on 2 October 1877. He would work at the navigation School in parallel to his work at the prison service until 31 August 1903 when he retired from that position.
On 25 February 1878 he was appointed as acting accountant at the Malmö Central Prison. This was renewed a couple of weeks later on 5 March and then, on 29 November 1878, he was appointed as accountant at Malmö Central Prison. He held :-
... the accountancy position at the Malmö Central Prison during thirty-five years, with "exceeding skill and rare zeal".On 14 June 1879 Dahlin married Bernhardina Adéle Oktavia Stackelberg (born 22 August 1846 in Malmö, died 29 September 1884 in Malmö), the daughter of Baron Major Bernt Adolf Gustav Hjalmar Louis Stackelberg and Maria Augusta Vilhelmina Lundbom. Their daughter Vera Julia Oktavia Dahlin was born at Malmö on 15 March 1880. She went on to study in Stockholm where she attended the Royal Conservatory of Music from 1897 to 1900. She died in Helsingborg on 19 February 1925. Dahlin and his wife also had a son, Bror Hjalmar Oskar Dahlin, born in 1881 and died in 1899.
Six years after Dahlin's wife died in 1884, he remarried on 13 August 1892. His second wife was Anna Fransiska Emilia Julie Ohlsen (born 8 September 1848 in Copenhagen, died 16 June 1926 in Helsingborg), the daughter of the gardener Jörgen Ernst Ohlsen.
Dahlin resigned his position at the prison service on 13 August 1913 when he reached the age of seventy. The authors of  write:-
At his resignation in 1913, the Swedish Prison and Probation Service expressed its gratitude for his "long and valued employment in the prison service and the great example that he had thus set for the cementation of the sound reputation of the correctional system". As a result of these merits the 1913 Swedish parliament granted him an increased pension.Dahlin was honoured with the "Second Award" from the Faculty of Humanities and Social Sciences of Uppsala University in 1875; the Royal Order of Vasa in 1895; and Jubilee Doctor on 30 May 1925. We note the sad fact that Dahlin's second wife and both his children died before him.
As to Dahlin's character and hobbies, the authors of  write:-
Dahlin's personality was characterised by devoutness, uncompromised probity, devoted service and irrepressible energy. He was in many ways a unique man, captivating through his sharp-wittedness and extensive knowledge. Interested in outdoor activities, he particularly practiced skiing, when the opportunity presented itself, as well as swimming. In his time he was one of Orphei Drängar's foremost second basses. At the age of sixty-three he took part in a choir tour of the United States.We note that the Orphei Drängar was a male choral society based in Uppsala.
Article by: J J O'Connor and E F Robertson