were an important group based in the Palu valley and related to the Toraja. Scholars relate that their control swayed under Ternate and Makassar, but this might have been a decision by the Dutch to give their vassals a chance to govern a difficult group. Padbruge commented that in the 1700s the Kaili population was significantly high and were a highly militant society. In the 1850s, a civil war erupted between the Kaili groups, including the Banawa, in which the Dutch colonial government decided to intervene. In the late 19th century the Sarasins journeyed through the Palu valley as part of a major initiative to bring the Kaili under Dutch rule. Some very surprising and interesting photographs were taken of shamans called Tadulako. Further Christian religious missions entered the area to make one of the most detailed ethnographic studies in the early 20th century. A Swede by the name of Walter Kaudern later studied much of the literature and produced a synthesis. Erskine Downs in the 1950s produced a summary of Kruyts and Andrianis work: "The religion of the Bare'e-Speaking Toradja of Central Celebes," which is invaluable for English-speaking researchers. One of the most recent publications is "When the bones are left," a study of the material culture of central Sulawesi, offering extensive analysis. Also worthy of study are the brilliant works of Monnig Atkinson on the Wana shamans who live in the Mori area. Population The 2000 census population of the provinces of Sulawesi was 14,946,488, about 7.25% of Indonesia's total population. By the 2010 Census the total had reached 17,371,782, and the 2020 Census produced a total of 19,896,951. The official estimate for mid 2021 was 20,076,987. The largest city on Sulawesi is Makassar. Religion Islam is the majority religion in Sulawesi. The conversion of the lowlands of the south western peninsula (South Sulawesi) to Islam occurred in the early 17th century. The kingdom of Luwu in the Gulf of Bone was the first to accept Islam in February 1605; the Makassar kingdom of Goa-Talloq, centred on the modern-day city of Makassar, followed suit in September. However, the Gorontalo and the Mongondow peoples of the northern peninsula largely converted to Islam only in the 19th century. Most Muslims are Sunnis. Christians form a substantial minority on the island. According to the demographer Toby Alice Volkman, 17% of Sulawesi's population is Protestant and less than 2% is Roman Catholic.