Lord of Storm's End in the middle years of the reign of King Aenys I and the chief of the great lords who set the boy Jaehaerys upon the Iron Throne after the fall of Maegor the Cruel. Born in 17 AC, the eldest of five Baratheon brothers — Borys, Garon, Ronnal, and Orryn after him — Rogar held the storm coast in his father's place from a young age, and when Maegor's tyranny grew unbearable to the lords he was among the first to declare for the boy prince Jaehaerys at Storm's End, sending word to Dragonstone and gathering a host. After the Iron Throne broke its own master in 48 AC and Maegor was found dead upon the spikes of his seat, Rogar rode to King's Landing at the head of his stormlords, was hailed in council as Hand of the King and Lord Protector of the Realm during the boy king's minority, and stood as the boy's right hand for nearly four years while Jaehaerys grew toward his crown.
In 49 AC he wed the dowager queen Alyssa Velaryon, mother to the new king, and got upon her two children of his own — Boremund, who would in time succeed him at Storm's End, and Princess Jocelyn, born late and with great cost to her mother. The marriage strained him with his own brothers and at last with the king, for in time Rogar quarrelled with Jaehaerys over the king's young will and was relieved of his offices in 54 AC; he returned home to Storm's End, never to sit the small council again. He came once more to court at Lord Tyland's request in 61 AC to bring his daughter Jocelyn before her half-brother the king, and died at his seat the year after, leaving Storm's End to Boremund and his Targaryen-born daughter in the keeping of Queen Alysanne.