Ruanda-Urundi in the context of "Belgian colonial empire"

The republics in the Commonwealth of Nations are the sovereign states in the organisation with a republican form of government. As of June 2022, 36 out of the 56 member states were republics. While King Charles III is the titular Head of the Commonwealth, he is not the head of state of the republican members. The King is however, the reigning monarch in the Commonwealth realms. The Head of the Commonwealth role does not carry with it any power; instead, it is a symbol of the free association of Commonwealth members.

Except for the former Portuguese possession of Mozambique, the former Belgian trust territory of Rwanda and the former French possessions of Gabon and Togo, they are all former British (or partly British) colonies or self-governing colonies that have evolved into republics. Most of the Commonwealth's members achieved independence while keeping the British monarch as their own individual head of state (in a form of personal union) and later became republics within the Commonwealth by abolishing the monarchy. In some other instances, the countries became republics after achieving independence from other former British colonies (as, for example, Bangladesh did from Pakistan in 1971 as a result of the Bangladesh Liberation War).

Indirect rule was a system of governance used by imperial powers to control parts of their empires. This was particularly used by colonial empires like the British Empire to control their possessions in Africa and Asia, which was done through pre-existing indigenous power structures. Indirect rule was used by various colonial rulers such as: the French in Algeria and Tunisia, the Dutch in the East Indies, the Portuguese in Angola and Mozambique and the Belgians in Rwanda and Burundi. These dependencies were often called "protectorates" or "trucial states".

Through this system, the day-to-day government and administration of both small and large areas were left in the hands of traditional rulers, who gained prestige and the stability and protection afforded by the Pax Britannica (in the case of British territories). Consequentially done at the cost of losing control of their external affairs, and often of taxation, communications, and other matters. It was usually carried out with a small number of European "advisors" effectively overseeing the government of large numbers of people spread over extensive areas.

The Kingdom of Burundi (French: Royaume du Burundi), also known as Kingdom of Urundi (Kirundi: Ubwami bw'Urundi), was a Bantu kingdom in the modern-day Republic of Burundi. The Ganwa monarchs (with the title of mwami) ruled over both Hutus and Tutsis. Created in the 16th century, the kingdom was preserved under German and Belgian colonial rule in the late 19th and early 20th century and was an independent state between 1962 and 1966.

Ethnic groups in Burundi include the three main indigenous groups of Hutu, Tutsi and Twa that have largely been emphasized in the study of the country's history due to their role in shaping it through conflict and consolidation. Burundi's ethnic make-up is similar to that of neighboring Rwanda. Additionally, recent immigration has also contributed to Burundi's ethnic diversity. Throughout the country's history, the relation between the ethnic groups has varied, largely depending on internal political, economic and social factors and also external factors such as colonialism. The pre-colonial era, despite having divisions between the three groups, saw greater ethnic cohesion and fluidity dependent on socioeconomic factors. During the colonial period under German and then Belgian rule, ethnic groups in Burundi experienced greater stratifications and solidification through biological arguments separating the groups and indirect colonial rule that increased group tensions. The post-independence Burundi has experienced recurring inter-ethnic violence especially in the political arena that has, in turn, spilled over to society at large leading to many casualties throughout the decades. The Arusha Agreement served to end the decades-long ethnic tensions, and the Burundian government has stated commitment to creating ethnic cohesion in the country since, yet recent waves of violence and controversies under the Pierre Nkurunziza leadership have worried some experts of potential resurfacing of ethnic violence. Given the changing nature of ethnicity and ethnic relations in the country, many scholars have approached the topic theoretically to come up with primordial, constructivist and mixed arguments or explanations on ethnicity in Burundi.

The Kingdom of Rwanda (also known as the Nyiginya Kingdom or Nyginya Dynasty) was a Bantu kingdom in modern-day Rwanda, which grew to be ruled by a Tutsi monarchy. It was one of the most centralized kingdoms in Central and East Africa. It was later annexed under German and Belgian colonial rule while retaining some of its autonomy. The Tutsi monarchy was abolished in 1961 after ethnic violence erupted between the Hutu and the Tutsi during the Rwandan Revolution which started in 1959. After a 1961 referendum, Rwanda became a Hutu-dominated republic and received its independence from Belgium in 1962.

After the revolution and abolition of the monarchy, the deposed Kigeli V eventually settled in the United States, and since then monarchists have maintained a court-in-exile outside of Rwanda. The current pretender to the Rwandan throne is Yuhi VI.

Mwambutsa IV Bangiricenge (6 May 1912 – 26 March 1977) was the penultimate king (mwami) of Burundi who ruled between 1915 and 1966. He succeeded to the throne on the death of his father Mutaga IV Mbikije (reigned 1908–15). Born while Burundi was under German colonial rule, Mwambutsa's reign mostly coincided with Belgian colonial rule (1916–62). The Belgians retained the monarchs of both Rwanda and Burundi under the policy of indirect rule.