cavalry of Aleksander Gosiewski. In early January 1622, the Swedes captured Valmiera, together with several smaller Livonian castles. Meanwhile, the forces under Hetman Radziwiłł grew to 3,000, which enabled the Lithuanians to respond better to Swedish attacks. On 7 January Radziwiłł recaptured Mitau, but because of a lack of artillery, he failed to seize its castle, whose garrison did not capitulate until 6 July. A few weeks later, in late July 1622, main Swedish forces reached Mittau, and a prolonged battle ensued. Since the battle turned into a stalemate, on 10 August 1622, both sides signed a truce, which in 1623 was prolonged until March 1625. During the negotiations, envoys of Gustav Adolf suggested a Swedish–Lithuanian union. Truce The Swedish eventually insisted on a truce due to financial problems of the Swedish Empire, as the costs of the war were too high for their treasury. Furthermore, in the autumn of 1621, the Polish–Ottoman War ended (see Battle of Khotyn (1621)), and the army of the Commonwealth was ready to march to Livonia. The truce, signed by the Lithuanians, enraged King Sigismund III Vasa, who planned to transfer all forces northwards, hoping that with the help of the Spanish Navy, he would be able to invade Sweden itself. Polish nobility and leaders such as Krzysztof Radziwiłł and Krzysztof Zbaraski disagreed with the royal plans. They wanted the King to agree to Swedish terms, and to relinquish the Swedish throne in exchange for a permanent peace treaty and Livonia. Radziwiłł emphasized the fact that after the reforms, the Swedish army was difficult to defeat, and Poland–Lithuania also needed a major overhaul of its armed forces, especially the infantry and artillery. The Commonwealth also needed a strong navy and specialized units of engineers, trained in erection of field fortifications. Regardless of the opinion of his generals, Sigismund III ordered construction of a fleet, which, with help from the Spanish Empire, was to transport the invading army to Sweden. In 1623, the Polish King met with the Starosta of Puck, Jan Wejher, telling him to build the fleet. However, from the very beginning, this was questioned by the powerful and semi-independent city of Gdańsk, whose government, under Swedish pressure, opposed the very idea of a Commonwealth fleet, and did not allow it to be anchored in its port. Under these circumstances, Sigismund III Wasa decided to expand the port and shipyard of Puck. In