The Borderlands Conflict, sometimes referred to as the Sixth Border Wars, coined by Steffon Blackgard as the Great Uprising, is a major conflict in the history the Borderlands. The conflict erupted after the three Baratheon kings placed their attention on the Borderlands, a vital tactical position that could give the ongoing War of the Five Kings a drastic turn. The conflict took a different direction after all three kings were killed and an anonymous rival house threatens House Blackgard's rule instead.
Ever since Trevyr Blackgard has passed away, House Greyjoy has sent their vassals, House Spyre to attack Blackgard while it lies vulnerable, resulting in the Assault of Blackgard, the first military engagement in the war.
Recently, Eddin Blackgard learned (after receiving a letter from Maester Caledon of Dunharrow) that the vassal house that was conspiring against the Blackgards was actually House Bergen. Their motives for doing this is yet to be known. It has also been revealed that, up until they were disbanded by order of the High Sparrow, House Bergen was aided by the Blackwatch, who were unaware that the Bergens were conspiring with Balon Greyjoy and later Euron Greyjoy.
Eventually, Eddin lost the war, with his own nephew, Steffon Blackgard, murdering him, his wife, their two sons, Eddard and Edwyn Blackgard, and claiming dominion over the Borderlands while the remaining members of the House who were still loyal to Eddin retreated to Sunhold under the protection of House Baerley.