Five Kage Summit

A is a meeting of all the Kage to discuss matters affecting their respective countries and the world at large. When a Kage wishes to meet with his or her fellow Kage, he notifies the others of a time and place to convene as well as how many bodyguards they may bring. Travel and mission restrictions are placed on all shinobi who will not be attending the meeting in the days before, during, and after so that no village can work against another while their Kage are gone.

Tailed Beasts
Shortly after the system of hidden villages was established, the first ever Kage Summit was convened in an unknown location by the First Hokage. In an attempt to balance the power between the villages and as a sign of goodwill, Konohagakure intended to distribute the tailed beasts it had acquired to the other villages. The Kazekage, however, noted that Sunagakure already had a tailed beast within their possession and instead asked for an alternative payment of a portion of the fertile land of the Land of Fire, their closest neighbour, and 30% of the asking price from each of the tailed beasts that the other nations would pay for. Most present were outraged by this and threatened war against Sunagakure, but the Hokage was able to quell their rage by speaking of his hopes for the future of the shinobi.

Akatsuki
Many decades after the first Kage Summit, another is convened in the Land of Iron by the Fourth Raikage. As a result of Akatsuki's growing activity in recent months to capture the tailed beasts and their jinchūriki, the Raikage wishes for the villages to unite against Akatsuki. Because many of the villages had employed Akatsuki in the past, the Raikage asks the Land of Iron's leader, Mifune, to mediate. Decades of conflict and competition between their villages make some of the Kage reluctant to cooperate or to admit Akatsuki is a real problem. It is only from the Hokage's revelation that Akatsuki is led by "Madara Uchiha" that the Kage see a threat.

Mifune suggests that the Kage form a coalition to oppose Akatsuki with the Hokage as its leader, citing the fact that only Konoha's tailed beast has yet to be captured. It is soon discovered that the Hokage is manipulating Mifune, prompting him to flee with his bodyguards when the meeting is attacked by Taka, an Akatsuki-affiliate. "Madara" confronts the remaining Kage shortly afterwards and, after failing to convince them to surrender their jinchūriki, he declares the start of the Fourth Shinobi World War. The four Kage and Mifune band together as the Allied Shinobi Forces in order to confront Akatsuki, with the Raikage as its leader. They also decide to invite Konoha's help by approaching Kakashi Hatake, not trusting the Hokage in light of his actions.

Moon Collision
Two years after the Fourth Shinobi World War ends, an emergency Kage Summit is convened to discuss how to handle the imminent crashing of the moon into the Earth.

Epilogue Meeting
Several years later, another Kage Summit is convened in Konohagakure by the Seventh Hokage. It is unknown what matters were discussed at the summit.

Meanwhile an Ex-Kage Summit was also being held by the former Kage at the Third Tsuchikage's Place. According to the Fifth Hokage it was just a simple meeting to drink together and complain.