REF: "Royalty for Commoners", Roderick W. Stuart, 1992, 2nd edition. A follower of Knut, King of England. Possibly not the father of Gytha.
Sources:
1. Abbrev: Ancestors of Henry II (Plantagenet) King of Englan Title: Douglas McMartin, Ancestors of Henry II (Plantagenet) King of England (15 Nov 1995)5 Nov 1995. Note: Call number:
WWW http://intermid.com/DoutBerg/genealog.y/royhenry.htm 2. Abbrev: University of Hull Royal Database (England) Title: Brian Tompsett, Dept of Computer Science, University of Hull Royal Database (England) (copyright 1994, 1995, 1996)base (England)base (England). copyright 1994, 1995, 1996. Note: Call number:
usually reliable but sometimes includes hypothetical lines, mythological figures, etc
WWW, University of Hull, Hull, UK HU6 7RX bct@tardis.ed.ac.uk 3. Abbrev: Europäische Stammtafeln (Isenburg edition) Title: Prince Wilhelm Karl von Isenburg, Europäische Stammtafeln (Isenburg edition) (Verlag von J.A. Stargardt, Marburg, pub. 1975, original 1953)tion)tion). Verlag von J.A. Stargardt, Marburg, pub. 1975, original 1953. Note: Call number:
selected charts in possession of J.H. Garner Page: Band II Table 70 Text: Jarl Thorkill (or Thurkill) Sprakalaeg, s of Styr-Bjorn Olafsson & Thyra Haraldsdottir, many sources do not show him as son of Thyra Haroldsdottir. 4. Abbrev: Pullen010502.FTW Title: Pullen010502.FTW Note: Call number: Text: Date of Import: Jan 5, 2002 5. Abbrev: University of Hull Royal Database (England) Title: Brian Tompsett, Dept of Computer Science, University of Hull Royal Database (England) (copyright 1994, 1995, 1996)base (England)base (England). copyright 1994, 1995, 1996. Note: Call number:
usually reliable but sometimes includes hypothetical lines, mythological figures, etc
WWW, University of Hull, Hull, UK HU6 7RX bct@tardis.ed.ac.uk Text: b abt 936, with his father Styrbjorn Olafsson of Sweden b abt 959. I reversed them.
Thorkils Styrbjornsson 
