pro-Austrian by conviction, he contrived even in this respect to carry with him the nation, often distrustful of the Germans. He also avoided serious complications and skirmishes with the powerful Turks. Livonia During Sigismund Augustus' reign, Livonia was in political turmoil. His father, Sigismund I, permitted Albert of Prussia to introduce the Protestant Reformation and secularize the southern part of the Teutonic Order State. Albert then established Europe's first Protestant state in the Duchy of Prussia in 1525, but under Polish suzerainty. However, his efforts to introduce Protestantism to the Livonian Brothers of the Sword in the northernmost part of the region was met with fierce resistance and divided the Livonian Confederation. When Albert's brother Wilhelm and Archbishop of Riga attempted to implement a Lutheran church order in his diocese, the Catholic estates rebelled and arrested both Wilhelm and his bishop coadjutor, Duke Christopher of Mecklenburg. As Prussia was a tributary state of the Polish Crown, Sigismund Augustus, a Catholic, was forced to intervene in favour of Protestant Albert and his brother Wilhelm. In July 1557 the Polish forces left for Livonia. The armed intervention proved to be successful; the Catholic Livonians surrendered and signed the Treaty of Pozvol on 14 September 1557. The agreement placed most Livonian territories under Polish protection and de facto became part of Poland. Gotthard Kettler, the last Master of the Order, was granted the newly established Duchy of Courland and Semigallia. Wilhelm was restored to his former position as archbishop on Sigismund's demand, with the Lutheran church order being enacted. The incorporation of Courland into the Polish sphere of influence created an alliance which threatened Russia's plans on expanding into the Baltic coast. Sigismund directed the alliance against Ivan the Terrible to protect lucrative trade routes in Livonia, thus creating a new valid casus belli against the Russian Tsardom. On 22 January 1558, Ivan invaded the Baltic states and started the Livonian War, which lasted 25 years until 1583. Russia's eventual defeat in the war legally partitioned Livonia between Poland (Latvia, southern Estonia) and Sweden (central-northern Estonia). The Polish sector became subsequently known as Polish Livonia or Inflanty; it was settled with colonists from Poland proper resulting in systematic polonisation of these lands. Northern Seven Years' War When the Kalmar Union between Sweden and Denmark was disbanded in 1523 due to Swedish resentment of Danish tyranny, Baltic trade became threatened. The port city of