http://fmg.ac/Projects/MedLands/HUNGARY.htm#_Toc146273214

Her parents: VAJK, son of GÉZA Prince of Hungary & his [first wife Sarolt of Transylvania] (Esztergom [967/75]-Buda 15 Aug 1038, bur Székesfehérvár). ... Prince István received a royal crown from Pope Sylvester II and was crowned ISTVÁN I King of Hungary 25 Dec 1000 or 1 Jan 1001. m (996) GISELA of Bavaria, daughter of HEINRICH II "der Zänker" Duke of Bavaria and Carinthia [Germany] & his wife Gisela of Burgundy ([985]-Passau 7 May 1065, bur Passau Kloster Niedernburg). King István & his wife had [five] children:

• 1. [OTTO (-young). ...
• 2. IMRE [Heinrich] ([1007]-killed Bihar 2 Nov 1031). ...
• 3. [BERNHARD . ...
• 4. [HEDWIG . According to the early 12th century Vita Eberhardi[352], the mother of Eberhard Graf von Nellenburg (son of Eberhard IV Graf im Zürichgau) was a daughter of István I King of Hungary, although it is somewhat surprising that such a prominent figure as King István, in far off Hungary, would have married his daughter to an obscure Swiss count. The Annales Scafhusenses record the marriage in 1009 of "Ebbo comes de Nellenburc" and "consobrinam Heinrici regis Hedewigam…de curie regis"[353]. If "consobrinam" is here used in its precise sense, Hedwig would have been the daughter of one of the sisters of Gisela, daughter of Conrad I King of Upper Burgundy. Hedwig founded Kloster Pfaffenschwabenheim as a widow[354]. If she was the daughter of King István, there is a remote possibility that she was the same daughter who supposedly married Edmund ætheling (see below), although if this is correct she would have been much older than her second husband. m (1009) EBERHARD [IV] Graf im Zürichgau, son of [MANGOLD [I] Graf im Zürichgau & his wife ---] (-[1030/34]).]
• 5. [daughter . ... m DOBOKA, son of ---.]

Possible relative of the kings of Hungary, precise relationship not known:

1. [HEDWIG of Hungary. ... m EDMUND of England, son of EDMUND "Ironsides" King of England & his wife Ældgyth --- (1016-before 1054).]

http://thepeerage.com/p10667.htm#i106661

Hedwig of Hungary1

F, #106661

Last Edited=12 May 2008

Hedwig of Hungary was the daughter of St. Stephen I Arpád, King of Hungary and Gisela von Bayern.1 She married Eberhard V Graf von Nellenburg.2 She married Edmund (?), son of Edmund II 'Ironside', King of England and Ealdgyth (?).1

Citations
[S11] Alison Weir, Britain's Royal Family: A Complete Genealogy (London, U.K.: The Bodley Head, 1999), page 28. Hereinafter cited as Britain's Royal Family. [S11] Alison Weir, Britain's Royal Family, page 29.