Sumbawa lies to the east of Java, Bali and Lombok. It is three times the size of Lombok with a population of around one million. Due to the small population spread out over a relatively large space, Sumbawa is often ignored by tourists as well as Indonesians. It marks the end of Indian influence and the beginning of what are sometimes referred to as the "pagan" eastern islands. Four principalities in western Sumbawa were dependencies of the Majapahit kingdom of eastern Java. Because of Sumbawa's natural resources it was regularly invaded by outside forces - Javanese, Dutch, Makassarese. The Dutch first arrived in 1605, but didn't effectively rule Sumbawa until the early 20th century. The Balinese kingdom of Gelgel ruled western Sumbawa for a short period as well. Islam was introduced via the Makassarese of Sulawesi. Because of the geography of the island Sumbawa is basically two islands. Sumbawa has historically had two linguistic groups which spoke languages that were mutually unitelligible. One group, centered in the western side of the island, speaks Sumbawanese which is similar to the Sasak language from Lombok; the second group in the east speaks Bima. The kingdoms located in Sumbawa Besar and Bima were the two focal points of Sumbawa.

Sumbawa lies within the Ring of Fire. It is a mountainous island with deep ridges and valleys. Sumbawa is the home of the volcano, Tambora. The 1815 eruption of Tambora was the largest in historic time despite the common assumption that the Krakatoa eruption was the largest. About 150 cubic kilometers of ash were erupted in 1815. Ash fell as far away as 800 miles. An estimated 92,000 people were killed by the eruption. Of this 92,000, 10,000 deaths were directly related to the bomb impacts, tephra fall, and lava flows. The other 82,000 deaths were caused by starvation, disease, and hunger. Famine was widespread due to crop failures during the "Year without a Summer." Daily minimum temperatures were abnormally low in the northern hemisphere from late spring to early autumn