Iceland has a short history of urban development because the industrial revolution did not reach there until the late nineteenth century. This was due to Iceland's isolation, colonial status and self-supporting economy. No towns were built in Iceland from the time of settlement in the ninth century until the second half of the nineteenth century. The only exception was an experiment with the wool industry in Reykjavik in the 1750s. In 1786 Reykjavik was the first settlement in Iceland to receive a royal declaration as an independent merchant township. Today, the population of the Reykjavik region is 160 000, but in 1901 it was only 6000. This paper outlines three waves of planning ideology that had a great impact on the planning of Reykjavik in this century. The first, the garden city ideology, was introduced in Iceland in the 1910s. This led to a productive period from 1915 to 1930, publication of the first textbook on urban planning in 1916, the first planning law in 1921, and the first town plan for Reykjavik in 1927. The second wave, the systematic transportation ideology, was brought to Iceland by Danish planning experts in the 1960s. Under it, the first master plan for Reykjavik was published in 1966, and the planning laws were revised in 1964. The third wave, the environmental-preservation ideology (Agenda 21) in the 1990s, was reflected in Reykjavik's master plan of 1996, with the main goal being to reduce traffic and pollution from cars. Furthermore, a proposal for the first regionalpreservation plan for the interior of Iceland has been introduced (Europe's largest unspoiled natural area), and new planning laws came into force in 1998.