Six and another city called Fred were both conquered by the four Shadowmasters, after they had already seized Pityus, Kiaulune, and Tragevec. Once Six and Fred became part of the Shadowlands, the leadership of Taglios actually became concerned about the threat which the Shadowmasters posed to their own sovereignty. Only then did the ruler of Taglios – the Prahbrindrah Drah – hire three foreigners (Willow Swan, Blade, and Cordy Mather) to lead Taglios into battle. These were the opening skirmishes of the Shadowmaster wars.
Willow Swan recounted this to Croaker and Lady during their meeting with the Prahbrindrah Drah and the city fathers of Taglios during Shadow Games. Six and Fred were not mentioned again in the Annals after this.
Six and the rest of the Shadowlands were liberated in Croaker's campaigns as Liberator sometime before or during She Is the Darkness. It almost certainly became part of Soulcatcher's massive Protectorate empire during or after the Kiaulune wars.