李成桂
When Taejo of Joseon ascended to the throne in 1392, he continued to use the laws of Goryeo, and the noble titles he gave to his sons, nephews, and sons-in-law were all "prince" (군). After the coup d'état in 1398, the system of noble titles changed: "duke" for king's sons, "marquis" for royal descendants, and "earl" for officers of senior first rank. This system was abolished in 1401 to avoid "usurping" the existing title laws of the more powerful Ming dynasty.