House Longwaters

During the Dance of the Dragons, two bastard brothers, Addam and Alyn of Hull, were acknowledged by Rhaenyra Targaryen as sons of Ser Laenor Velaryon and admitted into House Velaryon. Rumor held that their true father was Lord Corlys Velaryon, Laenor's grandfather, but whatever blood ran in them, both were named heirs to Driftmark. Addam died in the civil war; Alyn survived to inherit the lordship.

Alyn succeeded his grandfather, or perhaps father, as Lord of the Tides, Master of Driftmark, and head of House Velaryon. He earned the name Oakenfist through a string of exploits at sea: he fought Dalton Greyjoy, secured the release of Prince Viserys from captivity in Lys, and took part in the conquest of Dorne under King Daeron I Targaryen.

Married to Lady Baela Targaryen and father to her children, Alyn also loved Princess Elaena, the youngest daughter of King Aegon III and Queen Daenaera Velaryon. Jon and Jeyne Mares were born of that love. The sources don't say whether Alyn ever knew these children, or whether they were born only after he sailed on the voyage he never returned from.

Despite his bastard birth, Jon Mares became a celebrated knight, and his own son —whose name is still unknown— followed the same path. Because this son was born within wedlock, he escaped the stain his father and grandfather had carried, and from him the family took the name Longwaters.

Generations later, Rennifer Longwaters served as chief gaoler in the dungeons of the Red Keep. When Ser Jaime Lannister asked how Tyrion had escaped, Rennifer explained the workings of the cells while making sure to mention his lineage and the drop of dragon's blood he claimed to carry. Later, when Jaime went looking for Ser Ilyn Payne before setting out for the riverlands, it was Rennifer who told him where to find him.