谁嫁给了Catherine Birgersdotter of Bjelbo？

Catherine (fl. 1245–1289) was Princess consort of Anhalt-Zerbst by marriage to Siegfried I, Prince of Anhalt-Zerbst (c. 1230 – 1298), regent to Principality of Anhalt and a member of the House of Ascania.

In German sources, she is referred to as filia Regis Sweonum ("daughter of the Swedish King"). In 1961, Danish genealogist Sixten Otto Brenner interpreted this to mean she was the daughter of King Erik Eriksson of Sweden. However, Hans Gillingstam challenged this conclusion, arguing that it is more likely she was the daughter of Birger Jarl, the regent of Sweden. In the same sources, Birger Jarl's other daughter, Rikissa, is referred to with the same title.

Gillingstam notes that Siegfried and Catherine were already married in 1259, which is 15 or 16 years after Erik Eriksson married his queen, Katarina Sunesdotter. Gillingstam found this time span too short and also noted that Catherine would only have been named after her mother only if her mother had died soon after her birth. Since Katarina Sunesdotter died between 1251 and 1253, and Erik Eriksson died on 2 February 1250, this scenario is impossible.

According to some sources, Catherine may instead have belonged to the family of Counts of Gleichen, which had connections to Danish royal house.

西格弗里德一世（德語：Siegfried I., Fürst von Anhalt-Köthen；約1230年—1298年3月25日），阿斯坎尼王朝安哈爾特-策布斯特親王（1252年－1298年在位）。大熊阿爾布雷希特一世的曾孫，祖父為安哈爾特伯爵及巴倫斯特伯爵與及薩克森公爵的伯恩哈德。安哈爾特親王亨利一世與妻子圖林根領地伯爵赫爾曼一世的女兒伊姆加德的幼子。

1252年，亨利一世逝世並將安哈爾特親王國分為三份。身為幼子的西格弗里德一世繼承了采爾布斯特，由1253年起他用了科滕-德紹伯爵為號以識別他的領地。

1247年，當圖林根領地伯爵亨利·拉斯沛逝世後，圖林根爵位繼承戰爭爆發。通過他的母親，西格弗里德一世是圖林根領地伯爵赫爾曼一世的外孫，他在戰爭中佔領了普法爾茨，但是其後他放棄普法爾茨並交予韋廷王朝以換取金錢利益。

1259年10月17日，西格弗里德一世迎娶瑞典的實際統治者攝政伯爵比爾耶爾·馬格努斯的女兒嘉芙蓮，瑞典國王瓦爾德瑪·比耶松的妹妹。他們一共有十名兒女。

1290年，西格弗里德一世放棄統治權，而成為布道僧侶。長子阿爾布雷希特一世成為安哈爾特-策布斯特統治者。直至1298年，西格弗里德一世逝世，爵位由阿爾布雷希特一世繼承。