 In 1557, the trading treaty was completed, and in 1558, Edzard visited Sweden to meet Catherine and her sister Cecilia and chose one of them to complete the marriage treaty.Edzard chose Catherine, but the negotiations took a long time, so much so that Gustav Vasa stated in his frustration that it was a blessing that his daughter was at least neither "limped or blind".Edzard's mother, the dowager Regent Anna of Oldenburg, was afraid that the marriage would lead to Swedish domination, and therefore split the power in Ostfriesland between her sons, something which the king tried to prevent.