The rise in housing prices in Stockholm over the past 20 years is unprecedented in a historical perspective. The relationship between real estate prices and various fundamental factors is a highly controversial issue. Some argue that fundamental factors are responsible for the higher housing prices. Others warn of an imminent crash. A longer time horizon can add nuance to this discussion. Over the past 150 years, four real estate price crashes have occurred: 1905-1918, 1931-1955, 1979-1985 and 1990-1995. All four crashes followed an extended period of price increases, construction boom and economic crisis. The lessons learned from these crashes are still relevant. The main objective of the project is to reconstruct a historical real estate index for the inner city of Stockholm since the 17th century. This index will be used to analyze long-term trends and short-term fluctuations. The reconstruction of a real estate price index is complicated not least by the difficulty of measuring qualitative changes. Two methods used are either to follow only the sales price of the same dwelling or to follow the ratio between market price and assessed value. Both aim to keep quality constant, and both will be used in this study. For the earlier period, however, the index will be based on average price changes.