The homeland of the Bugis is the area around Lake Tempe and Lake Sidenreng in the Walennae Depression in the southwest peninsula of Sulawesi. It was here that the ancestors of the present-day Bugis settled, probably in the mid- to late second millennium BC. The area is rich in fish and wildlife and the annual fluctuation of Lake Tempe (a reservoir lake for the Bila and Walennae rivers) allows speculative planting of wet rice, while the hills can be farmed by swidden or shifting cultivation, wet rice, gathering and hunting. Around AD 1200 the availability of prestigious imported goods including Chinese and Southeast Asian ceramics and Gujerati print-block textiles, coupled with newly discovered sources of iron ore in Luwu stimulated an agrarian revolution which expanded from the great lakes region into the lowland plains to the east, south and west of the Walennae depression. This led over the next 400 years to the development of the major kingdoms of South Sulawesi, and the social transformation of chiefly societies into hierarchical proto-states.