The Thyllanorian kingdom of ancient times (in Edranish sources known as the First Empire of Andoras) was a kingdom founded by the Karth'maeres in modern-day Thyllanor, in the late First Era. Its two most prominent rulers, Vaerik Karth'maere and his son, Anders, ushered directly in the founding of the Karthmere dynasty. Over time, the name "Karth'maere", which at this point had been a title for the leader of the Tribe of Karth, eventually mutated into a surname with the influence of the newfound Andorasi tongues, and later, the Edrossi missionaries who converted the populace to the Two Paragons.
The kingdom itself was also notable for being the main reason for the ending of the First Era; all main powers on Doras Edrossi had recognized its sovereignty by 7,647 BC/1E 2656, which retroactively ushered in the Second Era (as determined by the Horological Council of Ceryne, who manages the rightful passage of time according to various calendars). Starting as the Kingdom of Karth, it began to spread south and southwest, and at its peak it ruled the entirety of modern day Thyllanor and the Kingsland, the majority of Raunerre in the north (southern Raunerre was under the control of numerous different lords of Old Edrane at the time), and about half of the Wetlands, with the tentative addition of Dimlight Pass that typically belonged to the Moonlyt Peaks; while formally part of the Thyllanorian kingdom, Dimlight's inhabitants never acted as such, and was among one of the first conquered lands to relinquish the Karth'maere's control over them by revolting. It collapsed only 20 years later in 7,627 BC/2E 20, however, due to infighting and the death of its main ruler, Anders. It is known that it negotiated terms with Edrane to ensure their independence, and the Thyllanorian kingdom's existence later inspired Old Edrane to unite as one princedom.