Gecekondu

[2] Before the gecekondu phenomenon, teneke mahalles (tin-can neighbourhoods) constituted the main pattern of informal housing starting from the late 19th century.

The term gecekondu gained popularity with the construction of informal settlements by migrants from rural Turkey in the 1950s when the mechanisation of agriculture created a significant surplus population in villages.

[3][4][5] The immigrants, including Roma, who fled Bulgarian and south Romanian cities after the 1877-78 Russo-Turkish War, were the earliest founders of teneke mahalles in different parts of Istanbul such as Kumkapı and Nişantaşı.

[9] “Coined by city residents, the term [gecekondu initially] reflected almost exclusively their negative reaction to the influx of the villagers who defied established urban norms.”[1] In common usage, it refers to the low cost apartment buildings or houses that were constructed in a very short time by people migrating from rural areas to the outskirts of the large cities.

Robert Neuwirth writes in his book Shadow Cities that these squatters are exploiting a legal loophole which states that if one starts building after dusk and moves into a completed house before dawn the next day without having been noticed by the authorities, then the next day the authorities are not permitted to tear the building down but instead must begin a legal proceeding in court (and thus it is more likely one can stay).