The stele was erected by Gwanggaeto’s son, King Jangsu 장수왕 in 414 AD. The reasons he did this was three-fold:
Honor his father
Commemorate King Gwanggaeto’s military triumphs and expansion of Goguryeo
Serve as a reminder to the rest of the world that it was his intent to continue in his father’s footsteps by continuing the expansion of Goguryeo.