Thaba Bosiu, The name Thaba Bosiu means the 'Mountain at Night'. It was in July,1824 when Moshoeshoe and his people took occupation of the mountain which his brother Mohale had reconnoitred.
He named the mountain Thaba Bosiu-Mountain at Night because he and his people arrived there in the evening and the essential protective work took him until late at night. Many years later the news to intimidate his enemies was spread that at night time the mountain grew larger than usual. This is where the Basotho nation was built. The fortress has eight springs and seven passes, the main one being Khubelu. Thaba Bosiu was never conquered by his invaders.
The mountain is flat-topped and it is situated in the valley of the Phuthiatsana River. It is about fifteen miles east of the junction of this river with Mohokare or Caledon that divides Lesotho from the Free State. It rises about 350 ft. from the surrounding valley and its summit is surrounded by a belt of perpendicular cliffs some 40 ft. high on the average.
haba Bosiu is a constituency and sandstone plateau with an area of approximately 2 km2 (0.77 sq mi) and a height of 1,804 meters above sea level. It is located between the Orange and Caledon Rivers in the Maseru District of Lesotho, 24 km east of the country's capital Maseru. It was once the capital of Lesotho, having been King Moshoeshoe's stronghold.
Thaba Bosiu was used as a hideout by Moshoeshoe I and his subjects after they migrated from Butha-Buthe in 1824 escaping the ravages of the Difaqane/Mfecane Wars. The plateau formed a natural fortress which protected the Basotho in times of war. Moshoeshoe I and his people took occupation of this mountain in July 1824. He named it Thaba Bosiu (loosely translated – Mountain at Night) because he and his people arrived at night. To intimidate his enemies, he spread news that the mountain grew larger at night. Moshoeshoe was able to offer cattle and protection to those fleeing the ravages of Mfecane/Difaqane Wars. When Moshoeshoe settled in Thaba Bosiu, he sent for many people to be rounded up by his regiments. They were given food and shelter. The plateau's large area meant it could hold enough livestock and provisions to support the people during a lengthy siege.
Once satisfied that they were safe, he sent the people out, but many remained under his rule. This gave birth to the Basotho nation; Thaba Bosiu served as a capital for his new Basotho nation. It also became the centre of organised resistance to European encroachment into the central plateau region of South Africa