According to geni.com[1], he is actually my 31st great grandfather.
Anonymized the first part of my line:
You → ********
your father → ********
his mother → ********
her mother → ********
her father → ** Johansen
his father → Johan Grove Kristoffersen
his father → Ingeborg Catharine Jentoft Henrichsdatter Klæboe
his mother → Henrich Johan Hansen Klæboe
her father → Maren Hansdatter Glein
his mother → Margaretha Johansdatter Grøn
her mother → Margrethe Christophersdatter Darre
her mother → Kristoffer Bjørnsen Bjørnsen
her father → Bjørn Rolfson Darre
his father → Maren Bjørnsdatter
his mother → Johanne Mattisdatter
her mother → Margreta Johannesdatter Kruckow
her mother → Anne Ludvigsdatter Barsebek
her mother → Magdalena Svare
her mother → Adelus Eringsdotter Erlingsdtr Tolstad, Hildugard
her mother → Elin Jonsdatter Hildugard Tolstad
her mother → Sigrid Erlingsdotter Bjarkøy
her mother → Elin Thoresdatter Bjarkøy
her mother → Ingebjørg Erlingsdatter Bjarkøy
her mother → Erling Alvsson Tornberg
her father → Ingeborg Bårdsdotter Rein
his mother → Bård Skule Guttormsson Rein
her father → Sigrid Torkjellsdotter Fugl
his mother → Hallkatla Sveinsdatter Av Aurland
her mother → Ingerid Svendsdatter of Denmark, Queen Consort of Norway
her mother → Sweyn II Estridson, King of Denmark
her father → Princess Estrid Margrethe (Margret), Of Svendsdatter
his mother → Sweyn I "Forkbeard", king of Denmark, Norway & England
her father → Harald "Blue Tooth", king of Denmark
his father
This starts to fall apart because of overlap -- for most of those people, he's thousands of their 30th-something great grandfather, not just one ancestor.
Anonymized the first part of my line:
You → ******** your father → ******** his mother → ******** her mother → ******** her father → ** Johansen his father → Johan Grove Kristoffersen his father → Ingeborg Catharine Jentoft Henrichsdatter Klæboe his mother → Henrich Johan Hansen Klæboe her father → Maren Hansdatter Glein his mother → Margaretha Johansdatter Grøn her mother → Margrethe Christophersdatter Darre her mother → Kristoffer Bjørnsen Bjørnsen her father → Bjørn Rolfson Darre his father → Maren Bjørnsdatter his mother → Johanne Mattisdatter her mother → Margreta Johannesdatter Kruckow her mother → Anne Ludvigsdatter Barsebek her mother → Magdalena Svare her mother → Adelus Eringsdotter Erlingsdtr Tolstad, Hildugard her mother → Elin Jonsdatter Hildugard Tolstad her mother → Sigrid Erlingsdotter Bjarkøy her mother → Elin Thoresdatter Bjarkøy her mother → Ingebjørg Erlingsdatter Bjarkøy her mother → Erling Alvsson Tornberg her father → Ingeborg Bårdsdotter Rein his mother → Bård Skule Guttormsson Rein her father → Sigrid Torkjellsdotter Fugl his mother → Hallkatla Sveinsdatter Av Aurland her mother → Ingerid Svendsdatter of Denmark, Queen Consort of Norway her mother → Sweyn II Estridson, King of Denmark her father → Princess Estrid Margrethe (Margret), Of Svendsdatter his mother → Sweyn I "Forkbeard", king of Denmark, Norway & England her father → Harald "Blue Tooth", king of Denmark his father
[1] https://www.geni.com/people/Harald-Blue-Tooth-king-of-Denmar...