The state's population is mostly Malay, with significant Chinese and Indian minorities.
Kedah has a long history; the Bujang Valley has remains of a Hindu-Buddhist kingdom that dates back to the 4th century, making it the oldest civilization of Peninsular Malaysia. The kingdom fell under the domination of Sumatra and then Thailand. The first sultan was Muzaffar Shah, who reigned from 1136 to 1179, and was followed by 27 others. At the end of the 18th century, the sultan at the time enlisted British assistance by ceding the island of Penang and then the coastal strip opposite the island, although Kedah was still captured by the Thais in 1821, who transferred control to the British in 1909 as part of the Bangkok Agreement.