8. Isak Gustav Isakinpka Bäck (Isaac Gustaf Eriksson ) was born on 26 Jan 1831 in Muonio, Övertorneå, Finland. He died on 12 Jan 1912.
Isak married Kristina Ulrika Johansdotter Alamattila daughter of Johan Persson Mattila and Ulrika Henriksdotter Regina on 16 Feb 1862. Kristina was born on 26 Dec 1841 in Muonio, Övertorneå, Finland. She died on 26 Jul 1905.
They had the following children:
+ 15 F i Marie Josefina Bäck was born on 2 Dec 1861. She died on 8 Sep 1896. 16 M ii Herman Bäck was born on 3 Jan 1864. He died on 11 Jan 1953 in Amerika. + 17 F iii Amanda Kristina Bäck was born on 6 Dec 1869. 18 M iv Karl Johan Bäck was born on 10 May 1874. He died on 10 Dec 1919. 19 M v Isak Bäck was born on 26 Dec 1879. He died on 20 Aug 1901.