Lucerys Velaryon is the second child of Rhaenrya Targaryen and Ser Laenor Velaryon, at least in Fire & Blood by George R. R. Martin. The TV adaptation, House of the Dragon, would say another man had a hand in Lucerys' birth. While Rhaenyra's other sons play major roles in the Dance of the Dragons, it was Lucerys who made the biggest impact.
Source：https://www.cbr.com/hotd-lucerys-velaryon-explained/
