A kingdom in N Sumatra is recorded by the 6th-cent. A.D. Chinese. By the 8th cent. Islam had arrived, and a number of Muslim kingdoms and sultanates were subsequently established in the region. Aceh (Achin) reached the height of its power in the early 17th cent. The Dutch gained control of the coast in 1873 and engaged in a partly successful effort to subdue the interior until c.1910.

Aceh also resisted Indonesian control and in 1959 was designated a special region with autonomy in religion, culture, and education. Late in 1976 the Movement for a Free Aceh (GAM) declared the province independent but was suppressed; guerrilla warfare resumed in the late 1980s and continued through the rest of the century. A peace agreement providing for greater Acehnese autonomy was signed in 2002, but with neither side willing to compromise, Indonesia ended the subsequent talks in 2003, imposed martial law (reduced to a state of emergency in 2004 and ended in 2005), and launched new attacks against the rebels.

Many coastal areas in Aceh were devastated by an intense offshore earthquake and resulting tsunami in Dec., 2004; some 166,000 died in the province. In the aftermath, the rebels and government held a series of talks aimed at ending the fighting. A new peace accord, calling for the rebels to disarm, government forces to be reduced, and for local self-government to be established in Aceh, was signed in Aug., 2005. Some 15,000 people are believed to died as a result of the conflict. An autonomy law for Aceh was passed by the Indonesian parliament in 2006, but some Acehnese criticized it for provisions that left the central government with more powers in Aceh than had been envisioned by the peace agreement. In Dec., 2006, Irawandi Yusuf, a former GAM rebel, was elected governor.