A moratorium is in effect on adding information from Fire and Blood until December 20th.
Moon of the Three Kings
The Moon of the Three Kings was a month near the end of the Dance of the Dragons when there were multiple "monarchs". These included two pretender kings, Trystane Truefyre, a hedge knight's squire, and Gaemon Palehair, the son of a whore.
King Aegon II Targaryen escaped King's Landing during its fall to Queen Rhaenyra Targaryen, his half-sister and rival monarch. Rhaenyra ruled the city for only half a year, before she abandoned King's Landing in the aftermath of riots during the fifth moon of 130 AC. The Shepherd, who had instigated the Storming of the Dragonpit, ruled much of the capital with his mob, while other parts fell into chaos.
The hedge knight Ser Perkin the Flea, a leader of the rioters, claimed that his squire, Trystane Truefyre, was a bastard son of the late Viserys I Targaryen, the father of Rhaenyra and Aegon. Perkin had previously been gathering support for the boy, and at some point after Rhaenyra's flight, he installed Trystane in the Red Keep.
The second pretender king was Gaemon Palehair, the four-year-old son of Essie, a whore who claimed the boy had been fathered by Aegon II. Given Aegon's philandering ways, this was not seen as improbable. Gaemon ruled from the House of Kisses atop Visenya's Hill and gathered thousands of followers. He issued a series of edicts, including a declaration that females should be equal to males in matters of inheritance. Mushroom claimed these edicts were almost certainly the work of Sylvenna Sand, a Dornish whore and the paramour of Essie.
Meanwhile, Aegon II, hiding on Dragonstone, recuperated from injuries suffered at Rook's Rest. With Rhaenyra on the mainland, Aegon's greens took her castle through the fall of Dragonstone. In the tenth moon of 130 AC, Rhaenyra was killed by Aegon's dragon, Sunfyre, when she returned to Dragonstone. Sunfyre succumbed to his own wounds in the twelfth moon of the year.
After mourning Sunfyre, Aegon II readied plans to recover the Iron Throne in chaotic King's Landing. Lord Borros Baratheon led men from the stormlands to bring order to the capital on the king's behalf. Ser Perkin was imprisoned, and Trystane Truefyre was executed once Aegon took the city, though not before he received the boon of knighthood. Essie admitted that Gaemon had been the son of an oarsman from Lys, and was hanged. Gaemon Palehair was arrested, but then accepted into Aegon's household.