###Answer the question from the input provided. Please answer from input only.

###Input: The first fortified settlements on the site of today's Warsaw were located in Bródno (9th/10th century) and Jazdów (12th/13th century). After Jazdów was raided by nearby clans and dukes, a new similar settlement was established on the site of a small fishing village called Warszowa. The Prince of Płock, Bolesław II of Masovia, established this settlement, the modern-day Warsaw, in about 1300. In the beginning of the 14th century it became one of the seats of the Dukes of Masovia, becoming the official capital of Masovian Duchy in 1413. 14th-century Warsaw's economy rested on mostly crafts and trade. Upon the extinction of the local ducal line, the duchy was reincorporated into the Polish Crown in 1526.

In 1529, Warsaw for the first time became the seat of the General Sejm, permanent from 1569. In 1573 the city gave its name to the Warsaw Confederation, formally establishing religious freedom in the Polish–Lithuanian Commonwealth. Due to its central location between the Commonwealth's capitals of Kraków and Vilnius, Warsaw became the capital of the Commonwealth and the Crown of the Kingdom of Poland when King Sigismund III Vasa moved his court from Kraków to Warsaw in 1596. In the following years the town expanded towards the suburbs. Several private independent districts were established, the property of aristocrats and the gentry, which were ruled by their own laws. Three times between 1655–1658 the city was under siege and three times it was taken and pillaged by the Swedish, Brandenburgian and Transylvanian forces.

Warsaw remained the capital of the Polish–Lithuanian Commonwealth until 1796, when it was annexed by the Kingdom of Prussia to become the capital of the province of South Prussia. Liberated by Napoleon's army in 1806, Warsaw was made the capital of the newly created Duchy of Warsaw. Following the Congress of Vienna of 1815, Warsaw became the centre of the Congress Poland, a constitutional monarchy under a personal union with Imperial Russia. The Royal University of Warsaw was established in 1816.

Warsaw was occupied by Germany from 4 August 1915 until November 1918. The Allied Armistice terms required in Article 12 that Germany withdraw from areas controlled by Russia in 1914, which included Warsaw. Germany did so, and underground leader Piłsudski returned to Warsaw on 11 November and set up what became the Second Polish Republic, with Warsaw the capital. In the course of the Polish-Bolshevik War of 1920, the huge Battle of Warsaw was fought on the eastern outskirts of the city in which the capital was successfully defended and the Red Army defeated. Poland stopped by itself the full brunt of the Red Army and defeated an idea of the "export of the revolution".

After the German Invasion of Poland on 1 September 1939 began the Second World War, Warsaw was defended till September 27. Central Poland, including Warsaw, came under the rule of the General Government, a German Nazi colonial administration. All higher education institutions were immediately closed and Warsaw's entire Jewish population – several hundred thousand, some 30% of the city – herded into the Warsaw Ghetto. The city would become the centre of urban resistance to Nazi rule in occupied Europe. When the order came to annihilate the ghetto as part of Hitler's "Final Solution" on 19 April 1943, Jewish fighters launched the Warsaw Ghetto Uprising. Despite being heavily outgunned and outnumbered, the Ghetto held out for almost a month. When the fighting ended, almost all survivors were massacred, with only a few managing to escape or hide.



###Question: Who did Warsaw serve as the seat for in 1529?

###Answer: {'answer':'General Sejm'}