Ladakh is the largest and the second least populous union territory of India. Ladakh is bordered by the Tibet Autonomous Region to the east, the Indian state of Himachal Pradesh to the south, both the Indian-administered union territory of Jammu and Kashmir and the Pakistan-administered Gilgit-Baltistan to the west and the southwest corner of Xinjiang across the Karakoram Pass in the far north. It extends from the Siachen Glacier in the Karakoram range to the north to the main Great Himalayas to the south. The main religious groups in the region are Muslims (mainly Shia) (46%), Buddhists (mainly Tibetan Buddhists) (40%), Hindus (12%) and others (2%). Ladakh is one of the most sparsely populated regions in India. Its culture and history are closely related to that of Tibet. Ladakh was established as a union territory of India on 31 October 2019, following the passage of the Jammu and Kashmir Reorganisation Act. Prior to that, it was part of the Jammu and Kashmir state.