Commonwealth leaders meet in Kigali on Friday to discuss cooperation on topics from trade to health to climate, against a backdrop of criticism of the host Rwanda's human rights record and of a British policy to deport asylum seekers there.
The Commonwealth, a club of 54 countries most of which are former British colonies, encompasses about a third of humanity and presents itself as a network of equal partners with shared goals such as democracy, peace and prosperity.
Britain's Prince Charles and Prime Minister Boris Johnson will attend an opening ceremony along with heads of state and government from most member countries, before the leaders hold two days of talks behind closed doors.
One item on the agenda will be applications by former French colonies Togo and Gabon to join the Commonwealth, a sign of disenchantment within France's sphere of influence in Africa and of the attractions of an English-speaking club.
The theme of the summit, "Delivering a Common Future: Connecting, Innovating, Transforming", offered few clues as to what outcomes were expected.
At previous summits, leaders have agreed on declarations and targets on specific challenges such as malaria, and some of the richer members have pledged funding for specific initiatives.
Some prominent countries, including South Africa, India, Pakistan, Australia and New Zealand sent more junior delegations led by ministers to Kigali.
Earlier this month, 24 civil society groups including Human Rights Watch said the Commonwealth's human rights mandate would be undermined if leaders failed to challenge Rwanda on its record.
They said the Rwandan government was responsible for abusive prosecutions, harassment and torture of dissidents, which Rwanda denies.
The hosting of the summit by Rwanda has also kept the spotlight on Britain's controversial policy to deport asylum seekers to the country.
Prince Charles was reported by British media to have described it as "appalling", an uneasy backdrop to his interactions with both Johnson and Rwandan President Paul Kagame at the summit. However, any tensions were unlikely to be aired in public.
Johnson, asked by Reuters on Thursday if he would visit detention centres prepared by the Rwandan authorities to receive asylum seekers from Britain, said he was "flat out" and would not be able to.
(Additional reporting by Andrew MacAskill; Writing by Estelle Shirbon, Editing by William Maclean)