began to build an impressive Gothic cathedral, now the Pelplin Abbey, using mainly bricks as construction material. According to the monastery's chronicle, work on the building was taken up already prior to 1294 by Mestwin II, Duke of Pomerania, and was completed during the second half of the 14th century, amounting to a building time of almost 200 years. The monastery was attached to the southern side of the cathedral. It was enlarged considerably during subsequent centuries. The cathedral of the Cistercians, now Pelplin Abbey, is recognized as one of the most important examples of sacral architecture in the Vistula region. As far as matters concerning the church were concerned, the region of Pelplin was at that time subordinated to the administration of the Diocese of Gniezno. Pelplin was part of the Duchy of Pomerania (Eastern/Gdańsk Pomerania), which in 1227 separated from Poland as a result of the fragmentation of the state. In 1282, Duke Mestwin II and Polish Duke Przemysł II (future King of Poland) signed the Treaty of Kępno, which transferred the suzerainty over Gdańsk Pomerania including Pelplin to Przemysł II and, subsequently, after Mestwin II's death in 1294, Pelplin was reintegrated with Poland. In 1310 the Teutonic Order captured Gdańsk Pomerania and incorporated it into the monastic State of the Teutonic Order. In 1454, Polish King Casimir IV Jagiellon signed the act of re-incorporation of the territory to the Kingdom of Poland, and in the Second Peace of Thorn of 1466, the Teutonic Knights renounced any claims to the region, and recognized it as part of Poland. Pelplin was since part of the Pomeranian Voivodeship in the autonomous province of Royal Prussia in the Greater Poland Province. In the following centuries several Polish Kings visited the Pelplin Abbey, among them Sigismund III Vasa and John III Sobieski. During the reformation, the last abbot of the monastery of Doberan moved in 1552 to the affiliated monastery of Pelplin. Partitions of Poland In 1772, during the First Partition of Poland by the Russia, Austria and Prussia, Pelplin was annexed into the Kingdom of Prussia, in 1773 it was included into the newly formed province West Prussia, composed from just annexed Polish territory, and the religious and political discrimination of the Poles greatly intensified. Pelplin was subjected to Germanisation policies. In 1819 the Pelplin monastery was suppressed. After the monastic buildings had been modified, they were utilized since 1824 as