Moshoeshoe’s reign coincided with the growth to power of the well-known Zulu king, Shaka. During this first part of the 1800s, Shaka raided many smaller clans along the Eastern coast of Southern Africa incorporating parts of them into his steadily growing Zulu chiefdom. Various small clans were forced to flee the wrath of the Zulu chief. Then an era of great wars of calamity followed. It was marked by a lot of aggression and ruin against the Sotho people by the invading Nguni clans. The attacks also forced Moshoeshoe to move his settlement to the Qiloane plateau. The name was later changed to Thaba Bosiu or "mountain of the night" because it was believed to be growing during the night. It proved to be an impassable stronghold against enemies.
The most significant role Moshoeshoe played as a diplomat was his acts of friendship towards his beaten enemies. He provided land and protection to various people and this strengthened the growing Basotho nation. His influence and followers grew with the integration of a number of refugees and victims of the wars of calamity.
By the latter part of the 1800s, Moshoeshoe established the nation of the Basotho. He was popularly known as Morena e Moholo/morena oa Basotho (Great chief/king of the Basotho).