While the modern-day land and maritime boundary dispute between Guyana and Venezuela over the Essequibo/Esequiba Region has its roots in the colonial era, for most of its existence, the frontier between the two States was considered operative and well established. In the 1840s, the British government had the border unilaterally surveyed, but the proposed line encroached on Venezuelan territorial claims. These differences in interpretation led to an arbitration (1899), followed by a bilateral demarcation agreement (1905). As Guyana approached independence from the United Kingdom in the early 1960s, Venezuela renewed its claims to Guyanese territory west of the Essequibo River. Guyana inherited this dispute and the framework for its resolution, but for the remainder of the twentieth century, the boundary dispute was not a major issue of contention between the two States.

In 1990, the United Nations began mediation efforts between Guyana and Venezuela to resolve the boundary dispute. Large oil reserves were discovered offshore the Essequibo/Esequiba Region in 2015, and the boundary dispute became a major issue. In 2018, resolution efforts for the dispute were moved at the United Nation’s recommendation to the International Court of Justice. Despite objections from Venezuela, the Court is currently reviewing the boundary dispute case.

The de facto boundary and Guyanese claim, as it was delimited by the 1899 Arbitration, follows a series of rivers, watersheds and other geographic features for 829 kilometers (515 miles) from the Atlantic coast to the tripoint with Brazil on Mount Roraima. Venezuela’s claim along the Essequibo River extends for 1,034 kilometers (643 miles) before reaching Brazilian territory. At stake is approximately 142,795 square kilometers of territory that is currently administered by Guyana. Offshore the disputed land territory is maritime space that was discovered to be rich in hydrocarbon resources, upping the stakes of the land boundary dispute.