Artifacts indicating human activity dating back to the early Stone Age 200,000 years ago have been found in the Kingdom of Swaziland. Prehistoric rock art paintings date from ca. 25,000 B.C. and continue up to the 19th century.

The earliest inhabitants of the area were Khoisan hunter-gatherers. They were largely replaced by the Bantu tribes during Bantu migrations who hailed from the Great Lakes regions of Eastern Africa. Evidence of agriculture and iron use dates from about the 4th century and people speaking languages ancestral to current Sotho and Nguni languages began settling no later than the 11th century. The Bantu people known as the Swazis established iron-working and settled farming colonies in the 15th century after crossing the Limpopo river. They experienced great economic pressure from the rival Ndwandwe clans from the south.

The country derives its name from a later King, Mswati I. However, Ngwane is an alternative name for Swaziland and Dlamini remains the surname of the royal family, while the name Nkosi means King.

The autonomy of the Swaziland Nation was dictated by British rule of southern Africa in the 19th and 20th centuries. In 1881 the British government signed a convention recognizing Swazi independence. However, controversial land and mineral rights concessions were made under the authority of the Foreign Jurisdiction Act of 1890 in terms of which the administration of Swaziland was also placed under that of the then South African Republic (Transvaal).

Swaziland was indirectly involved in the Second Boer War (1899–1902). The beginning of the conflict found it administrated by the South African Republic, with the colonial headquarters set at Bremersdorp. In September, 1899, with war considered imminent, the colonists started evacuating the area. Ngwane V of Swaziland (Bhunu) was informed that the area would be left in his care during the absence of the white residents. The Swaziland Police under Sgt Opperman started practicing for war while issuing rifles and ammunition to remaining burghers. On 4 October 1899, Special Commissioner Krogh issued an official notice of evacuation for "all white inhabitants" with the excecption of burghers eligible for active service. Most of the British subjects were escorted towards the border with Mozambique, women and other South African civilians were left heading for various destinations. People with dual nationality were still subject to the draft, though unwilling to fight against their own people. Unsurprisingly, several of them escaped towards Mozambique or the Colony of Natal.

It was not long before skirmishes involved the Swaziland forces. On 28 October 1899, the newly formed Swaziland Commando unit moved against a British police post at Kwaliweni. The South African unit counted about 200 burghers, while the outpost only had 20 men. Bhunu managed to warn the police post of the approaching attack. The police retreated towards Ingwavuma, seat of a magistrate. The Commando burned the abandoned post and a nearby shop to the ground. Then Joachim Ferrera led them towards Ingwavuma. The village was not better guarded and had to also be evacuated. The Swaziland Commando burned it to the ground, while the magistrate and his people escaped to Nongoma.

Meanwhile, the Swazi people had been warned by Piet Joubert to remain calm and not involve themselves in the conflict. Bhunu instead found himself unrestricted from colonial authorities for the first time. He soon felt free to settle old scores with political enemies. News of the violent deaths of diplomat Mnkonkoni Kunene and several others in time reached the Boer forces involved in the Siege of Ladysmith. Several of the dead had close ties to the colonial authorities. Joubert had to assure worried commanders that Swaziland was not turning against. Indeed, spies reported that Bhunu feared he had been bewitched. He was striking against whoever he suspected of the deed. On 10 December 1899, Bhunu died due to a serious illness. He had blamed it on sorcery, though contemporaries suspect it was alcohol-induced. His mother Labotsibeni Mdluli became regent. She set about eliminating the surviving advisors and favourites of Bhunu.

Swazi regiments were roaming the country during the internal conflicts. The South African authorities were worried that the violence could expand towards the south-western border of Swaziland, where Boer farms were cultivated by women and children. They had the farms evacuated and the population transferred to Piet Retief. The farmers from Piet Retief, Wakkerstroom and their vicinities had made a practice of trekking their ship into Swaziland for winter grazing. In January, 1900, Francis William Reitz, the State Secretary of the South African Republic, started issuing orders discouraging any sheep-herders from entering Swaziland. On 18 April 1900, any such entry was forbidden. The Swaziland Commando were by that point far from their initial homebase, fighting along the Tugela River.

The British had their own concerns about Swaziland. They suspected that supplies from Mozambique could be smuggled to the Boers through Swaziland. Queen-regent Labotsibeni was however attempting to maintain neutrality in the wider conflict, pre-occupied with securing the throne. Her grandson Sobhuza II of Swaziland was underage and there were other viable candidates for the throne among the House of Dlamini. In particular, Prince Masumphe. Masumphe was a cousin of Bhunu and a rival candidate for the throne since 1889. His line of the family maintained close relations with the Boers, the Prince himself educated at Pretoria. By May, 1900, the Queen was worried that the Boers would intervene against her in case of a succession dispute. She opened communications with the restored magistrate of Ingwavuma, arranging to flee to his area if needed.

Her messages were passed to the government of Natal and from there to Cape Town, the capital of the Cape Colony. A reply by Johannes Smuts assured her that the British had not forgotten about the Swazi and British representatives would reliably return to Swaziland at an early date. The message might have reflected Smuts' own ambitions but his authority on such matters was rather questionable. But Frederick Roberts, Baron Roberts, a high-ranking military officer, was also convinced to start diplomatic contacts with the Queen. His representatives were to persuade the queen-regent of three things. First, the need to prevent the Boers from occupying the mountains of the area. Second, the necessity of formally appealing for British protection. Third, to make clear that the indiscriminate murders in Swaziland would have to end.
The British contacts with the Swazi played a role in advance of their siege of Komatipoort, a nearby South African stronghold. In September 1900, once the town fell, the British were able to capture Barberton and its area. A number of Boers fled into Swaziland. Only for the Swazi to disarm them and confiscate their cattle. The end of South African presence in the area left open the question of what to do with Swaziland. Smuts had been campaigning since May to convince the British authorities to place Swaziland under their administration. By September, Smuts had gained some support from civil authorities. But not by military ones, since Roberts did not want to devote any of his forces to an invasion or occupation of the area. Nevertheless, Smuts attempted some diplomatic contacts with the Swazi. Not particularly successful ones. The indvuna Smuts met for discussions refused to give any information on the internal affairs of Swaziland or Boer activities.
The fall of Komatipoort resulted in increasing the importace of Swaziland for the Boers. To maintain their communications with diplomatic and trade contacts in Lourenço Marques, Mozambique, the Boers had to sent messengers through Swaziland. Which was difficult since British forces were allowed to pass through certain Swazi areas. By November 1900, the Queen was able to assure both Roberts and Smuts that she "was doing her best to drive Boers out of her country". A few armed burghers and their African allies, hostile to her government, were still active at times.

On 29 November 1900, Roberts was relieved of his command. His replacement was Herbert Kitchener, Baron Kitchener of Khartoum. By late December, Smuts contacted the military secretary office of Kitchener concerning the Swaziland situation. Smuts had secured the position of Resident Commissioner of Swaziland though the British had no actual authority over the area. He attempted to convince Kitchener it was time to establish a permanent military presence in Swaziland. With himself taking charge of the area. Kitchener had a different view. Starting his own correspondence with Labotsibeni, Kitchener insisted on three points. First, the Swazi were still required to not take part in the war. Second, no British forces would be send in Swaziland unless the area faced a Boer invasion. Third, the Swazis were now directly under the authority of the British Crown, owing their loyalty to Victoria of the United Kingdom.

In December 1900-January 1901, there were information that retreating Boers were attempting to flee through Swaziland. Eight British columns were sent to either force the Boer commandos to surrender or flee to Swaziland. A certain column under Horace Smith-Dorrien proceeded all the way to the Swaziland border, managing to capture several Boer wagons and large numbers of cattle and sheep on 9 February 1901. Most of the captured Boers were sent to the concentration camp of Volksrust. On February 11, another column under Edmund Allenby was positioned at the southern border of Swaziland. On 14 February, Smith-Dorrien's forces reached Amsterdam. There he was contacted by envoys of the Queen-regent, requesting aid in driving the Boers off her land. In response, the Imperial Light Horse and the Suffolk Regiment were send into Swaziland.

Joined by armed Swazis, the two regiments were able to capture about 30 Boers in an initial skirmish. However heavy rains soon slowed their advance through the country. On 28 February 1901, other 200 men of the British mounted infantry entered Swaziland. Under Lt-Col Henry, this force managed to locate and capture the transport convoy of the Piet Retief Commando. About 65 Boers were captured in the operation. The remnants of the Commando retreated towards the southern border of Swaziland, only to get captured by the British forces stationed there. By early March, Smith-Dorrien noted that the Swazis were pillaging Boer residences. By this time, Allenby had reached Mahamba and set camp there, Henry was pursuing another Boer wagon convoys and Queen-regent Labotsibeni was ordering her Impis to clear their land from the Boers. Henry eventually managed to return to Derby with several prisoners, while Allenby and his forces reached the vicinity of Hlatikulu. The burthers had to limit themselves to "the hills of southwestern Swaziland".

Surviving accounts from the Devonshire Regiment indicate that the Swazis were acting as "a ninth column, commanded by the Queen of the Swazis". On 8 March 1901, remnants of the Piet Retief Commando, accompanied by women and children, were attacked by forces supposedly under Chief Ntshingila Simelano. The latter consisted of about 40 men, including two riflemen. 13 Burghers and one African guide were killed, several wounded, the others were scattered. Some of the survivors later surrendered to the 18th Hussars. Ntshingila later denied any involvement in the massacre. In any case, the incident terrified several other Boers. Between 8 and 11 March, about 70 burghers and various women children chose to surrender to Allenby rather than face the Swazis. The British nevertheless warned Labotsibeni to cease further massacres.

On 11 April 1901, Louis Botha corresponded with Kitchener, complaining that British Officers were inducing the Swazis to fight against the Boers. Claiming the result was the indiscriminate murders of Burghers, women and children by Swazi commandos. Allenby attributed the killings partly to Swazi anxiety to counter Boer incursions into their territory and partly to their fear of Boer reprisals. That is what the Boers would do when the British eventually left. Allenby himself refused to allow large numbers of armed Swazis to join his column, though he still used a few of them as guides. Smuts finally entered Swaziland during this month, though unable to establish his authority over any British forces.

The presence of regular British troops allowed the Queen-regent to present to them her concerns over an irregular unit, "Steinaecker's Horse". Created early in the war as a unit of adventurers and mercenaries under British command, they were well-known for looting Boer property. But with the Boer inreasingly impoverished, they had turned their attention to the cattle of the Swazi. Labotsibeni complained to both sides that this unit consisted of common robbers occupying Bremersdorp. Botha responded by sending a Commansdo Unit against the Horse. They were to avoid antagonizing the Swazi in any way. The Swazi National Council agreed to let them pass. Between 21 and 23 July 1901, the Ermelo Commando succeeded in forcing most of the "Steinaecker's Horse" forces to retreat, capturing about 35 men, killing or wounding a few and burning Bremersdorp to the ground.

Both the British and the Boers continued to have access to Swaziland with occasional skirmishes occurring. On 8 November 1901, for example, the 13th Hussars captured 14 burghers near Mahamba. The skirmishes ended in February 1902 with the defeat of the final Boer unit in Swaziland.

Nevertheless, the Swaziland independence Constitution was promulgated by Britain in November 1963 in terms of which a legislative Council and an Executive Council were established. This development was opposed by the Swazi National Council (liqoqo).

Despite such opposition, elections took place and the first Legislative Council of Swaziland was constituted on 9 September 1964. Changes to the original constitution proposed by the Legislative Council were accepted by Britain and a new Constitution providing for a House of Assembly and Senate was drawn up. Elections under this Constitution were held in 1967. Since 1973, Swaziland has seen a rather quiet struggle between pro-multiparty activists and supporters of the current Tinkhundla (constituencies) System of governance or Grass Roots Democracy System.