People who spoke Austronesian languages first arrived in Sumatra around 500 BCE as part of the Austronesian expansion from Taiwan to Southeast Asia. With its location in the India-China sea trade route, several trading towns flourished, especially in the eastern coast, and were influenced by Indian religions. One of the earliest known kingdoms was Kantoli, which flourished in the 5th century CE in southern Sumatra. Kantoli was replaced by the Empire of Srivijaya and then later by the Kingdom of Samudra. Srivijaya was a Buddhist monarchy centred in what is now Palembang. Dominating the region through trade and conquest throughout the 7th to 9th centuries, the empire helped spread the Malay culture throughout Nusantara. The empire was a thalassocracy or maritime power that extended its influence from island to island. Palembang was a center for scholarly learning, and it was there the Chinese Buddhist pilgrim I Ching studied Sanskrit in 671 CE before departing for India. On his journey to China, he spent four years in Palembang translating Buddhist texts and writing two manuscripts.
Srivijayan influence waned in the 11th century after it was defeated by the Chola Empire of southern India. At the same time, Islam made its way to Sumatra through Arabs and Indian traders in the 6th and 7th centuries AD. By the late 13th century, the monarch of the Samudra kingdom had converted to Islam. Marco Polo visited the island in 1292, and Ibn Battuta visited twice during 1345–1346. Samudra was succeeded by the powerful Aceh Sultanate, which survived to the 20th century. With the coming of the Dutch, the many Sumatran princely states gradually fell under their control. Aceh, in the north, was the major obstacle, as the Dutch were involved in the long and costly Aceh War (1873–1903).
Sumatra came under the control of the Dutch East Indies and became a major producer of pepper, rubber, and oil. In the early and mid-twentieth century, Sumatran academics and leaders were important figures in Indonesia’s independence movements, such as : Mohammad Hatta (the first vice-president) and Sutan Sjahrir (the first prime minister).
The Great Sumatran fault, a strike-slip fault, runs the entire length of the island along its west coast. On 26 December 2004, the western coast and islands of Sumatra, particularly Aceh province, were struck by a tsunami following the Indian Ocean earthquake. More than 170,000 Indonesians were killed, primarily in Aceh. Other recent earthquakes to strike Sumatra include the 2005 Sumatra Earthquake and the October 2010 Sumatra earthquake.
from the wikipedia.org/wiki/Sumatra