<P> Swedish forces entered the Holy Roman Empire via the Duchy of Pomerania, which served as the Swedish bridgehead since the Treaty of Stettin (1630). After dismissing Wallenstein in 1630, Ferdinand II became dependent on the Catholic League . Gustavus Adolphus allied with France in the Treaty of Bärwalde (January 1631). France and Bavaria signed the secret Treaty of Fontainebleau (1631), but this was rendered irrelevant by Swedish attacks against Bavaria . At the Battle of Breitenfeld (1631), Gustavus Adolphus's forces defeated the Catholic League led by Tilly . A year later, they met again in another Protestant victory, this time accompanied by the death of Tilly . The upper hand had now switched from the Catholic side to the Protestant side, led by Sweden . In 1630, Sweden had paid at least 2,368,022 daler for its army of 42,000 men . In 1632, it contributed only one - fifth of that (476,439 daler) towards the cost of an army more than three times as large (149,000 men). This was possible due to subsidies from France, and the recruitment of prisoners (most of them taken at the Battle of Breitenfeld) into the Swedish army . </P> <P> Before that time, Sweden waged war with the Polish--Lithuanian Commonwealth and could not support the Protestant states properly . For that reason, the King Gustav II enlisted support of the Russian Tsar Michael I, who also fought the Polish--Lithuanian Commonwealth in hopes of regaining Smolensk . While a separate conflict, the Smolensk War became an integral part of Thirty Years' confrontation . </P> <P> The majority of mercenaries recruited by Gustavus Adolphus were German, but Scottish soldiers were also very numerous . These were composed of some 12,000 Scots already in service before the Swedes entered the war under the command of General Sir James Spens and colonels such as Sir Alexander Leslie, Sir Patrick Ruthven, and Sir John Hepburn . These were joined by a further 8,000 men under the command of James Marquis Hamilton . The total number of Scots in Swedish service by the end of the war is estimated at some 30,000 men, no less than 15 of whom served with the rank of major - general or above . </P> <P> With Tilly dead, Ferdinand II returned to the aid of Wallenstein and his large army . Wallenstein marched up to the south, threatening Gustavus Adolphus's supply chain . Gustavus Adolphus knew that Wallenstein was waiting for the attack and was prepared but found no other option . Wallenstein and Gustavus Adolphus clashed in the Battle of Lützen (1632), where the Swedes prevailed, but Gustavus Adolphus was killed . </P>

These countries have large populations of protestants. england the netherlands norway ireland spain