By the middle of February 1900 the town of Ladysmith had been besieged for over 100 days. The Boers held a line along the northern bank of the Thukela River that kept the relief forces at bay.
The British had tried to break through the Boer lines at Spioenkop on 23 & 24 January but had suffered a devastating defeat. Next, in the first week of February, they tested the strength of the Boer defence at Vaalkrans to the east of Spioenkop, but again failed.
Gen. Sir Redvers Buller had received orders from Field Marshal Lord Roberts to relieve Ladysmith "at all costs".
The British finally succeeded at the Battle of Thukela Heights - a series of engagements, repositioning of troops and final confrontation. This all took place northeast of Colenso around a series of hills and mountains known as the Thukela Heights. The action lasted for two weeks, from 12 to 28 February.
The Boers were defending the northern bank of the Thukela with 4500 men and several artillery pieces. The British swept towards the river and by 20 February had control of the south bank. The next day the British crossed the river near Fort Wylie and took the Colenso koppies after some fierce fighting.
The British force in the area was massive, over 15 battalions and some 70 guns, the Boers were out numbered and some began to desert, leaving just 3000 men to face the British.
Each day a Boer position was taken until finally on 27 February Buller launched an attack on the remaining Boer strongholds at Hart’s Hill, Railway Hill and Pieters Ridge. The Boers, sensing defeat began to fall back to their position at Mbulwana , north of Ladysmith.
The following day, just before sunset, the first British troops entered the town, thus ending a 118 day siege.