Of Gaemon IV's younger brothers, only Princes Valerion, Daemon and Maegor receive their own fiefs in the Conquest of Volantis. They get, respectively Selhorys, Volenye and Volanapos.
They are the eldest of his little brothers and they married the younger sisters of Princess Daena (daughter of Prince Rhaenor) as a way to unite the claims there. So it goes that they should be the ones to get the best rewards. His remaining three younger brothers and six younger sisters all married into Cadet Houses, in matrilineal marriages in the case of boys. It's possible some of the princesses married Volantenes in preparation for the Conquest too.
Now, as for Gaemon IV's children and the siblings of Gael II, the ones who receive fiefs and lands along the Rhoyne Basin, the Andalos Hills and the Grass Sea are:
Prince Valerion and Princess Saera, the children of Aelinor, each receive a city to themselves and their descendants. Valerion gets Norvos; Saera has Pentos.
Prince Aemon and Prince Rhaellion, children of Daena the Younger also gets their own cities. Aemon receives Qohor, Rhaellion gets Vaekys.
Prince Jaehaerys and Prince Daeron are the sons of Jaehaera. Jaehaerys gets Essaria, which wasn't destroyed by the Dothraki and Daeron gets Embrys.
Rhaenys' sons, Princes Valarr and Aethan get, respectively, the rebuilt city of Ny Sar and the new city of Aranea built from the ground up by the Empire on the eastern end of Rhoyne Basin (the unnamed river that flows into Rhoyne above Selhorys)
Kiera's twins, Prince Laenor and Princess Laena receive for themselves the rebuilt Ar Noy. Their younger brother Prince Aenar gets the rebuilt Ghoyan Drone.
Plus a whole lot of lesser cities and towns gets built all over the place or rebuilt from ruins left there like Sarhoy and Chroyane, to better integrate the new lands into the Empire, with migrants from Westeros and even from further East in Essos settling there.
But I figure that the two senior kids - barring those that married back into the main line - of each wife would be the neat solution to how to apportion the lands without alienating everyone and their pet dragon. There might be more Cadet Houses made out of lower branches of other Cadet Houses or Imperial House. Or else, the Princes and Princesses that get the lands make some very strategic marriages there.
Oh, and some of the younger kids and cousins without new lands instead get appointed as Archons of Imperial Cities, to oversee them in the name of the Emperor/Empress. Plus the vassals have new cadets made from their younger sons too, or else the local families gets coopted there.
Anyway, the number of cadets of House Targaryen more than fucking doubled from what it was before.
@zombiefishgirl @ms-katonic-of-tamriel