In 1578, the childless John did agree that the son of Catherine should be his heir, but this did not end the struggle. Catherine fully used her family connections for her policy and asked her ruling brothers to intervene in her benefit, while she herself used her connections in return: she assisted Charles with his export- and import business, she provided ships for the Swedish fleet in the war against Russia, and assisted in the negotiations for marriages for Charles and Elizabeth.[1] She is known to have protested against the marriage of her brother King John III to Gunilla Bielke in 1585.[2] In 1591, Edzard became sole regent, but in 1594, the Emden revolution erupted.