same laborers) Seongdeok also had a large fortress erected near the capital of Gyeongju that extended ten kilometers in circumference. According to the Samguk Yusa, a 13th-century Korean record of history and fable that deals with the period in question, the fortress (known as Mobeol prefectural fortress) required the labor of nearly 40,000 men, a massive mustering of manpower that is testimony of the increasing power of the centralized monarchy. The reign of Seongdeok also bears evidence of continued attempts at reforming the land system of Silla. The dispersal of “able–bodied land” (jeongjeon 丁田) is first mentioned as taking place in the twenty–first year of King Seongdeok (722). The exact nature of able–bodied land is disputed since almost no corroborating evidence remains. However, based on the title, it would seem to be land distributed to able bodied commoners, though whether to work or own outright is unclear. In any case, whatever its precise nature, it would appear to be an attempt to buttress royal authority by nurturing relations with the peasantry at the expense of the land holding aristocracy. In fitting culmination to Seongdeok‘s reign, and symptomatic of improving relations with Tang, in 735 Tang Emperor Xuanzong formally granted the Silla king the territory south of the Pae River (the modern Taedong River running through Pyongyang), land that had been held at least formally by Tang ever since the 7th century and the Tang–Silla campaigns that had toppled Goguryeo. Seongdeok‘s reign was one of relative prosperity and peace. As one Korean scholar has contended, during his rule "...the paramount authority of the throne was finally secured, and with this accomplished the kingdom at last was able to enjoy unaccustomed domestic tranquility.". According to one account in the Samguk Sagi, Seongdeok invented Korea's first water clock, in Korean nugak 漏刻, in 718. However, this is likely a mistaken rendering of Nugakjeon 漏刻典, for elsewhere the Samguk Sagi relates that in 718 was established for the first time the Nugakjeon, or Office of Timekeeping. Regarding the death date of Seongdeok, as period Chinese histories record that in the second month of 737 a Tang envoy was dispatched to confer investiture upon Seongdeok's successor (later King Hyoseong) as King of Silla, it has been posited that King Seongdeok in fact died in 736. Family Parents Father: Sinmun of Silla (r. 681–692) (김정명) Grandfather: Munmu of Silla (626–681; reigned 661–681 Grandmother: Queen Jaeui, of