The Treaty of Sumatra (Sumatra-tractaat) was an international convention signed on 2 November 1871 between the United Kingdom and the Kingdom of the Netherlands that altered colonial spheres of influence in Sumatra.
Key Provisions
Under Article I of the treaty, Great Britain withdrew all formal reservations against the expansion of Dutch sovereignty across Sumatra, effectively nullifying the independence guarantee contained in the Treaty of London. In exchange, the Netherlands ceded its colonial possessions on the Gold Coast (Guinea, West Africa) to Britain and granted equal commercial rights to British traders in Sumatra.
The treaty granted the Netherlands a free hand in Aceh, leading directly to the First Aceh Expedition in 1873.
See Also
Source
De expeditiën naar Atjeh 1873-1874, W.W.F. Herfkens, Koninklijke Militaire Academie, 1900, p. 4.