Aldalómë, Old Thracian for Twilight of the Trees, refers to the breaking of the royal elven House of Thracia into three branches at the dawn of the Third Age.
The sacrificial Second Banishment involving Princess Galadriel Thracia in the Manster Rebellion, the disappearance of First Prince Elros Thracia, and the death of High King Elrond I Thracia in the Arawn Losstarot War as well as the fall of the forest of the Kingdom of Thracia in the aftermath of the Explosion, which had reshaped the Land of the Living, left surviving Princes Celen Thracia, Sindaros Thracia, and Thylus Thracia divided over who should succeed the late king to the throne. Celen tried to claim the throne by right of being the eldest surviving son but was contested by his brothers who disagreed with his views. These disagreements escalated into heated arguments, eventually leading the brothers going their separate ways with their retainers and allies and founding the three elven kingdoms of Celenia with the main Thracian bloodline, Mori'Taure with the royal cadet branch of the House of Sindaros, and Folsworth Woods with the royal cadet branch of the House of Thylus.
Some elven families who chose not to swear allegiance to any of the brothers went their separate ways as well, founding autonomous elven dominions such as Kemet and Traquine, further dividing the elves across the many continents that formed. The great division weakened the elves significantly although it led to the emergence of an enigmatic and heavily debated prophecy which foretold that a golden emperor would rise among elves and lead to the discovery of the Silver Throne of the High King which had been lost in the Explosion one day, uniting the scattered elves into one nation again.