The G7, which holds its first formal summit in nearly two years this weekend in Cornwall, southwest England, is a grouping of major wealthy powers created in 1975.
Originally established as a vehicle for leading industrialised democracies to discuss the global economy, it has expanded its scope to issues such as peace and security, climate change and now the coronavirus pandemic.
Last year's gathering in the United States was cancelled due to the global health crisis.
The usually annual summit is staged in the country which holds the rotating presidency. The G7 members are Britain, Canada, France, Germany, Italy, Japan and the United States.
Its leaders last met in the French resort of Biarritz in August 2019, amid trans-Atlantic tensions between then-US president Donald Trump and other Western allies.
In 2018, in Quebec, Canada, Trump walked out without signing the traditional end-of-summit joint declaration. But he was on best behaviour in Biarritz and the event passed off with far more typical bonhomie and unity.
This year's event, taking place Friday to Sunday in Carbis Bay, near St Ives, is seen by host Prime Minister Boris Johnson as a key opportunity to assert his post-Brexit "Global Britain" strategy.
Discussions are set to be dominated by the world's recovery from the pandemic and countries' varying success at mass vaccination drives.
Climate change will also feature prominently as Britain is also hosting the pivotal COP26 environmental summit in November in Glasgow, Scotland.
Meanwhile improving cooperation on global trade -- after the tumult of the Trump years, when trade tensions multiplied -- and girls' access to education, are other British priorities.
The meetings date back to Rambouillet in France in 1975, in the wake of the first oil shock, during which oil prices soared.
Six current members took part in this first "G6", and were joined a year later by Canada making the "G7".
The initiative came from French president Valery Giscard d'Estaing, who wanted to elevate to the top-level meetings already held by the countries' finance ministers on burning economic issues.
During the 1980s, tensions between the East and West during the Cold War gave a more political slant to the meetings.
The Williamsburg summit in 1983 adopted, for the first time, a declaration on security in Europe.
The text of support for the policies of US president Ronald Reagan towards Moscow was adopted despite the reservations of French president Francois Mitterrand.
The collapse of the Soviet Union in 1991 proved a game changer.
Russia, which attended the summit as a guest in 1992, was in 1998 allowed for the first time to attend all summit meetings. The grouping was officially renamed the "G8".
From 1999, during a period of successive financial crises, the G8 was criticised for being an exclusive club.
The rich powers therefore also started meeting with emerging countries in the new "G20" grouping, in an attempt to resolve or avoid these crises.
Italy, the current G20 president, will host a two-day gathering of the larger grouping in Rome from October 30.
In 2001, the G8 summit in the Italian city of Genoa was overshadowed by violent demonstrations by anti-globalisation protesters which left one person dead.
The protesters challenged the usefulness and legitimacy of the G8 and called for the cancellation of the poorest countries' debts.
Protests dogged other G8 summits, prompting organisers to tighten security.
In 2014, Vladimir Putin's Russia was suspended from the G8 after it annexed Ukraine's Crimea peninsula and sanctions were imposed on Moscow.
The G8 summit planned for that year in Russia was cancelled and the G8 reverted to being the G7.
In the run-up to the 2019 summit, Trump called for Russia to be readmitted, arguing it would be "much more appropriate to have Russia in".
But he found little support for the move among other Western countries.