The city of Leverkusen is a product of economic growth in the Rhine-Ruhr region. It was rural area until the late 19th century. The present city is made up of several villages, originally called Wiesdorf, Opladen, Schlebusch, Steinbüchel, Rheindorf and Bergisch-Neukirchen. Wiesdorf, dating back to the 12th century, was chosen by the apothecary Carl Leverkus for establishing a dye factory in 1860. The factory was taken over by the Bayer company in 1891. The company moved its office to Wiesdorf in 1912, turning the town into the centre of German chemical industry.