Construction of Marienburg Castle, also known as Malbork Castle, began in 1276 to serve as a stronghold for the Order of the Teutonic Knights. Originally engaging in conquests to bring Christianity to the pagan peoples of eastern Europe, the order established their own kingdom in 1283. The castle complex was built across an expansive site in three different phases until it came under control of the kingdom of Poland in 1457. One of the distinguishing features of the castle, besides its size, was its red brick construction – the result of a scarcity of suitable stone in the region. The three main areas of the castle were increasingly fortified from north to south. The outer castle, which stretches north along the river, would have served as the military garrison, whilst the middle castle and upper castle to the south would have been the centres of administration and the monastic order respectively.