Seongdeok of Silla

Timeline

1. 702–704Geumseong (Gyeongju) · GyeongjuHis elder brother Hyoseong died without an heir, and Seongdeok was enthroned by the Hwabaek council as the 33rd monarch of Unified Silla, beginning a reign of thirty-five years.
2. 705–731Territory of Unified Silla · Korean PeninsulaHe repeatedly issued amnesties and relief edicts in response to floods, droughts, famine, and epidemic; implemented a land-grant system for farmers, and built fortifications and dredged waterways to stabilize the agricultural and corvée base.
3. 715–733Geumseong (Gyeongju) · GyeongjuTaking advantage of the standoff between Tang and Balhae, he improved relations with Tang, which recognized his rule south of the Yalu River; he built forts on the northern frontier, established a water-clock office, and exchanged envoys, consolidating Unified Silla's position in the Northeast Asian order.
4. 734–737Geumseong (Gyeongju) · GyeongjuIn his later years he designated sons including Hyoseong and Gyeongdeok as successors; he died in 737 and was buried near the Seongdeok royal tomb in Gyeongju, posthumously honored by Tang as Grand Guardian of the Heir Apparent, one of the longest-reigning monarchs of mid-period Silla.