Lord of Storm's End during the reigns of Maekar I and Aegon V Targaryen, a knight famed in the lists for the great booming laugh with which he answered every blow laid against him — Lyonel the Laughing Storm, beloved of the smallfolk for his cheer and reckoned by many the finest lance of his age. As a young knight and heir to Storm's End he rode in the tourney at Ashford Meadow in 209 AC, where he was unhorsed by Prince Baelor Breakspear and where the hedge knight called Ser Duncan the Tall took the field as Prince Baelor's man in the famous trial of seven. He served the crown through the First and Second Blackfyre risings and grew into a great lord of the stormlands, his cousin-by-degrees on the throne and his halls full of song.
In 237 AC King Aegon V plighted his eldest son Prince Duncan the Small to one of Lord Lyonel's daughters as part of the king's policy of binding the great houses to the throne by marriage; when the prince broke that betrothal a year on to wed instead the hedge-girl Jenny of Oldstones, Lyonel took the slight as no Baratheon could bear, doffed his fealty, declared himself Storm King after the manner of the Durrandons, and called his banners. The rising lasted only a season — King Aegon brought a host into the stormlands and laid siege to Storm's End, and there in the muddy fields beyond his own gates Lyonel met Ser Duncan the Tall, now Lord Commander of the Kingsguard and his old friend, in single combat for the peace. The Laughing Storm was beaten down at last, yielded his cause, and was reconciled to the throne under terms struck by the Lord Hand: his line was forgiven, his lordship restored, and the king's youngest daughter Princess Rhaelle Targaryen was promised to his heir Ormund in time to come — the marriage that would in the next generation set Targaryen blood in the veins of the three brothers who would one day cast that house down.