The Third Arvessan War of Succession was a major international war fought from 1247 to 1273 AB. It began when the Imperial State of Khargorath asserted its claim to the vacant Arvessan imperial throne and opened a campaign to force recognition of that claim. Khargorath's government argued that the imperial succession had passed through an old dynastic marriage into House Korvakh and sought to establish itself as the legitimate successor to the former Arvessan Empire.

The initial Khargorathi campaign was fought across northern Occara, where every state bordering Khargorath eventually entered the conflict against it. Khargorathi armies nevertheless achieved major early successes and advanced beyond Occara into Mediath. At the greatest extent of the war, Khargorathi forces and military administrations operated across enormous distances, with their campaigns contributing directly to the collapse of the Mediathan states of Norvayne and Kars.

The war expanded far beyond the original dispute over the imperial succession. Existing rivalries, alliances, separatist movements, religious conflicts, and territorial ambitions drew additional states into the fighting. Wars that might otherwise have remained regional became connected to the larger conflict, and by its later years the Third Succession War involved powers across much of Veyrath. Fighting took place on land and at sea, while commerce raiding, blockades, occupation, rebellion, and economic disruption affected states well removed from the principal fronts.

Khargorath's position gradually deteriorated as the war spread across multiple fronts. Within territories claimed or controlled by the Imperial State, independence movements also gained strength. The Hravnskar Rising developed into a Skorvann war of independence, while Zhergost and Kharneth likewise broke from Khargorathi rule. In Mediath, the conflict also contributed to the struggle that produced the independent Ekbir Caliphate from territory formerly ruled by the Asharan Sultanate. The Skorvann League remains one of the principal states created by the postwar settlement.

By 1273 AB, Khargorath could no longer secure its imperial objectives or defeat the coalition opposing it. The war ended with the Concord of Vraakheld, which terminated the major hostilities and established much of the postwar political order. Khargorath abandoned its attempt to secure the Arvessan throne and recognized the independence of the Skorvann League, the Maritime State of Zhergost, and the Kingdom of Kharneth. The settlement also recognized the independence of the Ekbir Caliphate from the Asharan Sultanate.

The Third Arvessan War of Succession remains the defining international conflict of the present generation. 14 Veyrathian years (about 9.6 Cycles) after its conclusion, borders established during the settlement remain heavily defended, veterans and refugees remain politically influential, and relations between Khargorath and the states that emerged from its defeat remain tense.