This is my compilation of information on how all of Maas’s books are connected and some conclusions/theories I drew from the information. 

Please note that all page numbers were taken from hardback versions of the three books from which quotes were taken, so page numbers may not be the same in the paperback versions. 

A Court of Thorns and Roses Series (Prythian)

– The Fae were once ruled by a race called the Daglan who fed on magic and over 15,000 years before the events of ACOTR. The Fae rebelled against their oppressors over 15,000 years prior to ACOTR and become the dominant species.

~ “The Fae were not the first masters of this world. According to our oldest legends, most now forgotten, we were created by beings who were near-gods – and monsters. The Daglan. They ruled for millennia, and enslaved us and the humans. They were petty and cruel and drank the magic of the land like wine” (Maas, ACOSF, 554)

– There were hints that there were four items in the Dread Trove in ACOSF

~ “A fourth object lay on the altar, veiled in shadow. But she couldn’t make out more than a gleam of age worn bone -” (Maas, ACOSF, 548)

– The sword Gwydion disappeared around the same time as the Dread Trove, about 15,000 years prior to ACOTR

~ ““No one has been able to create a magic sword in more than ten thousand years,” Amren said. “The last one Made, the great blade Gwydion, vanished around the time the last of the Trove went missing” (Maas, ACOSF, 443)

– Gwydion was lost due to the machinations of the High King’s wife and top general

~ “It had belonged to a true Fae High King in Prythian, as there had been in Hybern. He had united the lands, its people – and for a while, with that sword, peace had reigned. Until he had been betrayed by his own queen and fiercest general, and lost the sword to them, and the lands fell into darkness once more” (Maas, ACOSF, 443)

– The island that holds the Prison was mentioned in A Courst of Mist and Fury as possibly being an eighth court before the Prison was put there. 

– During the events of A Court of Silver Flames, a red shooting star appears on Starfall. Feyre and Rhysand act a bit strange after seeing it

~ “The mood hadn’t been helped by a rare red star blasting across the sky one day – an ill omen, Nesta had heard the priestesses muttering. Cassian reported that even Rhys had been rattled by it, seeming unusually contemplative afterward” (Maas, ACOSF, 634)

Throne of Glass Series (Erilea)

– Blood oaths are sworn by drinking the blood of the one you wish to swear to. As a result their will becomes your own and you can’t disobey, only delay, otherwise you die. 

– At the end of Kingdom of Ash, Aelin travels through multiple realms while trying to get back to her own after sending the gods back to their home planet

– Two that she passes through are Midgard (Crescent City) and Prythian (ACOTR).

~ “She passed through a world where a great city had been built along the curve of a river, the buildings impossibly tall and glimmering with lights” (Maas, KoA 800)

~ “She passed through a world of snowcapped mountains … But it slowed her. That winged male’s power slowed her, just enough” (Maas, KoA, 800 – 801)

Crescent City Series (Midgard)

– All of the Vanir originated on different planets and that they colonized Midgard 15000 years ago

~ “The Midgard shifter were Fae from a different planet. All the Fae in that world shared their form with an animal” (Maas, HoSaB, 762)

– Tharion drank the blood of the Viper Queen to get away from the River Queen

– The Asteri used to rule the Fae of Midgard on their home planet but were usurped 1000 years before Midgard’s colonization, 

~ “Your ancestors wielded the Horn and another Fae object that allowed them to enter this world. Stolen, of course, from their original masters – our people. Our people, who built fearsome warriors in that world to be their army. All of them prototypes for the angels in this one. And all of them traitors to their creators, joining the Fae to overthrow my brothers and sisters a thousand years before we arrived in Midgard” (Maas, HoSaB, 761)

– The land the Midgardian Fae hail from is described as very similar to Prythian

~ “Not your kind of Fae of course – your breed swelled in a lovely, verdant land, rich with magic. If it’s of any interest to you, your Starborn bloodline specifically hailed from a small isle. a few miles from the mainland. And while the mainland had all manner of climes, the isle existed in beautiful, near-permanent twilight” (Maas 762)

~ “The knife could have been the twin of the Starsword: black hilted and bladed. It was its twin. The Starsword began to hum within its sheath, glittering white light leaking from where leather met the dark hilt. The dagger – The male dropped the dagger to the plush carpet. All of them retreated as it flared with dark light, as if in answer. Alpha and Omega. “Gwydion,” the dark-haired female whispered, indicating the Starsword” (Maas, HoSaB, 796)

Conclusions/Theories

– The Fae of Midgard are descended from the Fae of Prythian that travelled to Midgard 15,000 years prior to the events of ACOTR, 1,000 years after overthrowing the Aster/Daglani.

– The Starborn Fae are descendants of Night Court High Fae or Fae from the possible eigth court mentioned in ACOMF.

– The queen and general that stole Gwydion and killed the Fae High King was Prince Pelias and Queen Theia, and they brought Luna’s Horn and some of their people to Midgard when given the opportunity by the Asteri/Daglan

– The Midgardian Fae prophecy about greatness/victory for the Fae when sword and dagger are reunited refers to the Starsword/Gwydion and Truth Teller, Azriel’s dagger

– The Shifters of Midgard are descendants of Fae originally from Erilea that crossed over 15,000 years prior to the events of Throne of Glass. Note that this is 14,000 years before the first wars between the Valg and the Fae

– The events of A Court of Silver Flames and Kingdom of Ash occur within the same year.