When after-war Germany was in need of workers, the German government had to recruit people from overseas. They recruited then from the south of Europe. Initially, the workers came from Italy, then from Spain and Greece. Then in 1961, Germany also made a pact with Turkey to supply workers. Initially, neither the Germans, nor the Turks thought that they would be staying more than two years, as mentioned in their recruitment treaties. That is the main reason that no steps were taken for the integration of these people. The main reason why these people stayed back was the income they generated was too little to return to Turkey and start anything there.
On the other hand, the German economy did not want to lose skilled workers or hire new workers that need to be trained again. Also, the next generation of Turkish workers that had been born in Germany was now of school going age and their parents did not want to disturb their education.
Some Turkish workers did go back to their homeland, and this happened during the 1966-67, when the German economy had slowed down. Later when the economy revived, they came back. However, during the next recession of 1974-75 and 1981-1984, they preferred to stay back in Germany.
Today there remains only one-quarter of the number of Turks, who came to Germany initially. Out of these, more than half have immigrated as family members and about 17% of the adult Turks in Germany were born here. They form the largest population of foreigners living in Germany. They live mainly in the high industrialization zones, since that was where the first generation had started their jobs from.
The present economic crisis has hit the Turks with equal force as it has done to other industrial places. There is high unemployment rate as the jobs in the industry are cut.