PORTLAND – While negotiating the treaty that ended their war over Manchuria and Korea, Russian and Japanese delegates attended ballgames and cocktail parties in Maine, and even paid a visit to York Beach.

A series of events that begins this weekend will mark the 100th anniversary of the Treaty of Portsmouth, signed in New Hampshire on Sept. 5, 1905, to end the yearlong Russo-Japanese war.

A Saturday night event at the Green Acre Baha’i School in Eliot honors the centennial of a prayer meeting that took place while the war still raged. The school’s founder was the only woman to attend the treaty’s signing.

The school still provides religious instruction and fellowship for followers of the Baha’i faith, a worldwide, monotheistic religion whose central principle is unity.

A hundred years ago, famous singers performed the Japanese and Russian national anthems, and the audience prayed for the war to end.

This weekend’s gathering does not just commemorate that event, said Jim Sacco, co-administrator of the school.

“Our re-enacting this event in 2004 is really kind of a restatement of our desire and the desire of those who will join us to bring the nations of the world together,” he said.

At the time, the Russo-Japanese war was the largest ever in terms of casualties and costs to Japan and Russia, said Chip Noon, a member of the Portsmouth Peace Treaty Anniversary Committee.

Portsmouth was chosen as a neutral site to host negotiations because the Portsmouth Naval Shipyard provided ocean access and good security.

Over the course of negotiations, which began that August, negotiators learned that “local people had the ability to influence international events,” said Chuck Doleac, co-chair of the Portsmouth Peace Treaty Anniversary Committee.