the oldest mention of the buildings in the block is from the year 1420, where there was two stone houses along österlånggatan. between the houses, a now-abandoned alley went through the block. by the water lied a wooden keep, it was torn around the year 1430. later during the 1400s, sten sture the elder let the elderly begin the foundation work for a building, probably intended as a warehouse, in the southwest part of the block. the construction project is mentioned in stockholms tänkebok (a type of protocol book used in the medieval period) from the year 1492. construction stalled in 1495 as the area was hit by a massive fire.