evidence: In December 2023, Venezuelan President Nicolás Maduro threatened to annex Essequibo, the territory west of the Essequibo river, which constitutes two thirds of the neighbouring State of Guyana, and incorporate it into Venezuela as Guyana Esequiba. These notes trace the history of the almost 200-year dispute between Venezuela and the British colony of British Guiana (formed from three former Dutch colonies in 1831), which became the independent republic of Guyana in 1966 over the territory between the rivers Orinoco and Essequibo. In October 1899 an arbitration tribunal, before which the United States represented Venezuelan interests, awarded 95% of the disputed territory to Britain. The decision was accepted by Venezuela until 1962, when President Rómulo Betancourt declared the award null and void and resuscitated Venezuela´s claim to sovereignty over Essequibo. The 1966 Geneva Agreement between Venezuela and Britain/Guyana to reach an agreement satisfactory to both sides failed, and no progress on the issue was made during the following decades. With the discovery of oil offshore Essequibo in 2015, Venezuela intensified its claim to the territory. This led eventually to Maduro´s decision in 2023 to take unilateral action.