It evolved from small wild cats, about 7 different species here and there around the world. It is believed, aside from the human tendency to be drawn to infant animals, that it was kept and originally domesticated because of its excellent ability to kill rats and mice, which were otherwise destroying family grain storage. The cats that could tolerate human company and not become mean were the ones people kept, and these bred in the households.
The modern house cat evolved from the Greek Island of Cyprus. It is also a place where various animal species were introduced in 7500BC. The Ancient Egyptians were the very first people to domesticate the cat as a means of controlling vermin and other pests. Cats were also used to protect the food stores. Read more on http://www.catsinfo.com/history.html.