The eastward settlement (Ostsiedlung) by Germans became pronounced in Medieval times, and was often through invitation of local rulers who valued their industry, skills and martial prowess. Colonies in 12th-century Transylvania and Carpathian Galicia originated in this manner, and Catherine the Great solicited the influx of the Volga Germans. The Teutonic Knights controlled East Prussia for centuries, promoting German settlement, while the commercial empire of the Hanseatic League dispersed German merchants throughout the Baltic. The defeat of the Ottomans at Mohacs (1687) prompted the Habsburgs to encourage the settlement of the adjoining Danubian plains with Grenzers (‘Frontiersmen’), both to re-cultivate the battle-scarred country and to act as militias against further Ottoman incursion. In 1886, Bismarck’s Prussian Settlement Commission organized the planned transplantation of Germans (and displacement of Poles) from West Prussia. At the same time, German Mennonites fleeing religious persecution (others went west to America) formed settlements in Volhynia in Russia.