• https://en.wikipedia.org/wiki/Grimelda_of_Hungary

Grimelda of Hungary[1][2] was a Hungarian noblewoman and a dogaressa of Venice by marriage to Doge Otto Orseolo (r. 1009—1026). She was the daughter of Géza, Grand Prince of the Hungarians and Princess Sarolt.

Grimelda[3] married the Doge Otto Orseolo (r. 1009—1026). She followed Otto to Constantinople after his deposition.[4] Otto and Grimelda’s children were Peter, King of Hungary and Frozza Orseolo.

LA SUCCESSIONE CRONOLOGICA DELLE DOGARESSE

Elena (o Grimelda) principessa D'Ungheria 1009-1026

• http://www.veneziamuseo.it/REPUBBLICA/repdoge10.htm

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..nel 1011, sposò Geiza, figlia del re d’Ungheria e sorella del futuro s. Stefano...

• https://www.treccani.it/enciclopedia/ottone-orseolo_(Dizionario-Bio...

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-http://fmg.ac/Projects/MedLands/HUNGARY.htm#GrimeldaMPietroOrseoloB
--- of Hungary, daughter of GÉZA Prince of Hungary & his second wife Adelajda of Poland ([989]-1026). Her parentage is confirmed by Herimannus who names "Petrum, sororis suæ [=Stephanus Ungariorum rex] filium, de Venetia natum" when recording his accession in 1038[345]. Chronology suggests that she was the daughter of Prince Géza's second marriage but the primary source which confirms this has not so far been identified. Her marriage is confirmed by the Gesta Hungarorum which names "Petrum Venetum filium sororis suæ…cuius pater dux fuerat Venetorum" as successor to King István[346]. As Pietro Orseolo was Doge from 1009 to the early 1020s, he is the only possible Venetian ruler to whom this can relate. Andrea Dandulo´s Chronicon Venetum records the marriage "Otto Ursiolo dux" and "filiam Geyzæ regis Hungarorum et sororem Stephani", dated to 1009 from the context[347].

m (1009) PIETRO OTTONE Orseolo, son of PIETRO Orseolo II Doge of Venice & his wife Maria --- ([989]-Constantinople 1031). Named "OTTONE" at his confirmation at Verona 996, after his sponsor Emperor Otto III. His father associated him with the Dogeship after the death of his older brother Giovanni. He was elected Doge of Venice in 1009 in succession to his father. Unpopular in Venice for aggrandizing his family, he was forced to flee the city for Istria in [1022/23], but was recalled by the Venetians after the sacking of Grado by Poppo von Treffen Patriarch of Aquileia. Following further scandals over church appointments, he was deposed as Doge in 1026 and sent to Constantinople.

Pietro Orseolo & his wife had two children: 

Arpad family

-http://genealogy.euweb.cz/arpad/arpad1.html
The Magyars were a nomadic tribe who plundered Europe in late 9th/early 10th centuries
One Ügyek; m.Emese, dau.of Pr Önedbelia of Dentümoger; they had a son:
Álmos, *820, +Transylvania ca 895, had a son:
Árpád, Prince of Hungary, +907; he settled in what is now Hungary in about 900, though they continued to ravage western Europe til their defeat by Emperor Otto I in 955. He had issue:

• ...
• A5. Zaltas (Zoltán), Prince of Hungary (907-948)
  • B1. Taksony, Prince of Hungary (955-ca 972), *ca 905, +ca 972
    • C1. Géza, Great Prince of Hungary (ca 972-997), *ca 945, +1.2.997; 1m: ca 967 Sarolta (repudiated shortly after 975, +after 988), dau.of Prince Gyula of Transylvania; 2m: ca 985 Adelajda (+after 997), widow of his brother Michael
      • D1. [1m.] Judith, +after 987; m.985 (div 987) King Boleslav I of Poland (*967 +17.6.1025)
      • D2. [1m.] a daughter ; m.shortly before 985 Sizzo, Count in Thuringia
      • D3. [1m.] a daughter, +after 988; m.987 (he repudiated her 988) Gabriel-Radomir, Tsar of the Bulgarians
      • D4. [1m.] Saint István I (Stephen I), Prince of Hungary (997-1000), in 1000 became King of Hungary (1000-38) and the first Hungarian ruler to become a Christian, cr 25.12.1000/1.1.1001, canonised 20.8.1083, *969/75, +15.8.1038, bur Székesfehérvár; m.996 Gisela of Bavaria (*985, +7.5.1065)
        • ...
      • D5. [2m.] Skolasztika, a nun
      • D6. Maria, +1026; m.1009 Otone Orseolo, Doge of Venice
      • D7. [2m.] a daughter; m.1005/10 Sámuel Aba, King of Hungary (1041-44), +murdered 1044, bur Abasár
        • ...

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unsorced birth c.988 removed

little curiosity

Probably it must have been one of this type of marriages that then forced the "dogaresse of Venice" to bring the husband's COA to clarify who was marrying whom and who was to serve what.