Short answers, pulled from the story.
Lord Rosebery used the phrase Commonwealth of Nations on the 18th of January 1884 while standing in Adelaide, South Australia. This event marked an early conceptual shift from imperial rule to voluntary association among colonies gaining independence.
The London Declaration passed in April 1949 allowed India to remain in the Commonwealth as a republic if it accepted the British Sovereign as Head of the Commonwealth. This moment redefined membership beyond monarchy and enabled other republics like Ghana, Nigeria, and Jamaica to join without severing ties.
Shirley Ayorkor Botchwey of Ghana currently leads the Commonwealth Secretariat as secretary-general. She succeeded Patricia Scotland after serving two four-year terms and follows Arnold Smith, Sir Shridath Ramphal, and Chief Emeka Anyaoku who held previous roles.
Togo and Gabon joined the Commonwealth in 2022 as former French territories that were never under British rule. Togolese foreign minister Robert Dussey expected membership would help citizens learn English and expand access to education and culture while trade between Togo and Britain rose by 94 percent within two years of joining.
Zimbabwe withdrew from the Commonwealth organisation in 2003 after being suspended in 2002 over electoral and land reform policies under Robert Mugabe's ZANU-PF government. The suspension occurred following a decision by the Commonwealth Heads of Government Meeting regarding human rights violations.