Jens Marinus Jensen was born 1 Oct 1865 to Jens Christian Nielsen and Sine Jensen in Gunderup parish, Aalborg.
https://www.sa.dk/ao-soegesider/da/billedviser?epid=21584090#356809,70446810 (https://www.sa.dk/ao-soegesider/da/billedviser?epid=21584090#356809,70446810)
He was confirmed under that name in 1880,
https://www.sa.dk/ao-soegesider/da/billedviser?epid=21584090#356818,70447241 (https://www.sa.dk/ao-soegesider/da/billedviser?epid=21584090#356818,70447241)
and got married under the same name in 1892.
https://www.sa.dk/ao-soegesider/da/billedviser?epid=17124628#165780,27851293 (https://www.sa.dk/ao-soegesider/da/billedviser?epid=17124628#165780,27851293)
His first child was born/baptized Kristian Jensen in 1893.
https://www.sa.dk/ao-soegesider/da/billedviser?epid=17124628#165780,27851174 (https://www.sa.dk/ao-soegesider/da/billedviser?epid=17124628#165780,27851174)
But after his mother died in 1902,
https://www.sa.dk/ao-soegesider/da/billedviser?epid=17123244#163106,27398819 (https://www.sa.dk/ao-soegesider/da/billedviser?epid=17123244#163106,27398819)
in 1905 he appears to have changed his surname to Rasmussen and many of the church records were updated to reflect that.
His father did not die until 1910.
https://www.sa.dk/ao-soegesider/da/billedviser?epid=17123244#163107,27399062 (https://www.sa.dk/ao-soegesider/da/billedviser?epid=17123244#163107,27399062)
Any ideas why he made this change this late in life (about age 40)? I know this was the time frame the government was encouraging adopting fixed family surnames. His grandfather's surname happened to be Rasmussen. And which surname should I use? I tend to use birth names.
Art
Jensen is a very common name in Denmark. Maybe that's why he wanted to change his surname to Rasmussen, which was his
paternal grandfather's surname (patronymic).
I suggest you use the surname Rasmussen, but add information about the surname being Jensen from 1865 until 21 Aug. 1905.
Another possibiliity is to use the surname Jensen and add information that it was changed to Rasmussen 21 Aug. 1905.
Venlig hilsen
Inger Toudal
The 1904 law concerning surnames actually gave people the possibility to acquire a surname that their father or grandfather was
known under: https://themis.dk/synopsis/docs/Artikler/Navnet_det_er_stadig_Jensen.html
Venlig hilsen
Inger
You will find him under the name Jens Marinus Rasmussen already in the Census 1906
Census 1906: Aalborg Amt, Hellum Herred. Komdrup Sogn.
Jens Marinus Ramussen 1/10 1865.
Lasine Karoline Rasmussen. 19/11 1868.
+ children
Kilde (page 6 bottom + page 7): https://www.sa.dk/ao-soegesider/da/billedviser?bsid=11382#11382,295004
You will likely find him in Census 1911, 1916, 1921 and 1925 in Komdrup Sogn all under the name Jens Marinus Rasmussen.
Died: 27. April 1927 in Komdrup Sogn.
Buried: 11. Juli 1927 in Komdrup Kirkegaard.
Name: Jens Marinus Rasmussen.
Gaardejer i Komdrup Sogn.
Born: Gunderup By & Sogn, Fleskum Herred, 1. Oktober 1865.
Wife: efterlevende (still living) Larsine Caroline Rasmussen.
Last common address: Komdrup By.
Age: 61 Aar.
Cause of Death: Nephrosclerosis uræmia. [Uremia = Kidney disorder with urine poisoning in the blood; Nephrosclerosis = hardening of the walls of the small arteries and arterioles (small arteries that convey blood from arteries to the even smaller capillaries) of the kidney. This condition is caused by hypertension (high blood pressure)]
Kilde (s. 141, nr 1): https://www.sa.dk/ao-soegesider/da/billedviser?epid=17124628#165781,27851487
PS: I would call him "Jens Marinus - (1865-1905) Jensen/Rasmussen (1905-1927)" or something like that in my files cool)
or "Jens Marinus Jensen (from 1905-1927 Rasmussen)".
When I do genealogy I always find the birth name more important than later name changes, as we most often trace our lines backwards in time.
Thanks Inger and Niels!
I decided to use the Rasmussen name for those whose names were changed and added notes that they were born with the Jensen surname but in 1905 it was legally changed to Rasmussen.
Art