Complex sentence: For this feat, Lê Văn Thịnh was promoted to the position of chancellor of the Lý Dynasty (Thái sư), the highest position in the royal court only behind the emperor.
Split into simpler sentences: For this feat, Lê Văn Thịnh was promoted to the position of chancellor of the Lý Dynasty (Thái sư). This was the second-highest position in the royal court and was only behind the emperor.