Before the Soviet invasion, Dushanbe consisted of narrow streets with adobe buildings. The development of the 1920s, soon after the Soviet invasion, laid the groundwork for future development and established the beginning of the city. In the 1930s, constructivist architecture began to gain prominence along with the building of larger structures, often made out of concrete. Several architects played a major role in the city's construction in a group headed by Peter Vaulin. He drew up a piece of legislation called "On the construction of the city of Dushanbe" which the city adopted on 27 April 1927. He implemented a constructivist design in the city, possibly inspired by his meeting with Le Corbusier in Moscow in 1929.