He was upset about his marriage proposal to Catherine Jagiellon,[3][4] more so when John, on his own accord, loaned out money to the Poles and in return received many Polish fortresses in the Baltic as collateral, which legally he had no right to do.

[3][5] On August 26, a delegation from Poland requested an audience with the Danish king, Frederick II to discuss an alliance.

[10] The next target of the Swedes was Weissenstein, which was technically under Swedish rule, however, the nobility there showed strong sympathy to the Poles.

On October 16, John married Catherine, he also sent Sigismund another large sum of money, and in return received even more castles, those being Weissenstein, Helmet, Karkus, Ermes, Ruijen, Burtnik, and Trikaten.

[3] Once again, the Swedes were met with success, in late 1562, Karkus' defenders agreed to capitulate and let the Swedish garrison into the city.

[3] The main reason for the Swedish successes was that Eric XIV was able to pledge all available resources to Livonia since Sweden was not involved in any other war at the time.

[3][10][13] After the Swedes had conquered Karkus, the amount of troops in Livonia was reduced, although Sweden remained militarily stronger than its neighbors in the area.