He assisted his father in leading the country and strengthening royal authority, which had been severely weakened due to humiliation brought upon by the Later Yan, who dug up the grave of King Micheon.
[3] Sosurim is considered to have strengthened the centralization of authority in Goguryeo, by establishing state religious institutions to transcend tribal factionalism.
The development of centralized government system was largely attributed to reconciliation policy of Sosurim with its southern opponent, Baekje.
Under full-pledged support of royal family, it is said the first temple, Heungguk monastery of Korean kingdoms was supposedly constructed around the capital.
[6] Although he was not able to avenge the death of his father and previous Goguryeo ruler, King Gogugwon, he did play a major role in setting up the foundations that made the great conquests of his nephew and later ruler of Goguryeo, King Gwanggaeto the Great achieve reckless subjugations.