LOS ANGELES — When groups of ethnic Polish, Slovene, Slovak and Hungarian Catholics in Cleveland began protesting orders by their local bishop that closed their churches, they were given little chance of reversing the decision.

The churches were shuttered in a massive retrenchment of Cleveland’s urban core in 2010, striking at the Slavic and other ethnic European congregations that were founded by waves of immigrants from the wars and humanitarian catastrophes over the last century. The parishes claimed that Bishop Richard Lennon, head of the Cleveland diocese, had begun an attack on the ethnic churches.

But after two years of sidewalk vigils, letter-writing campaigns and legal action at the Vatican, the parishioners appear to have won a historic victory against their local diocese. A Vatican court, the Congregation of the Clergy, has ordered as many as 13 of the shuttered churches reopened.

“We will really celebrate when we meet inside our church, not on the sidewalk,” said Wojtek Fleszar, a truck driver who has led prayer vigils each Sunday on the street outside of the shuttered St. Casimir, long a center of the local Polish diaspora. “We have been praying for two years outside the church and, believe me, the weather here in Cleveland is something ridiculous.”

Protests were held outside the locked doors at other churches, including the Slovak parish at St. Wendelin, the Hungarian parish at St. Emerik and another Slovak parish at St. John. Other nonethnic parishes, such as the massive St. Patrick church, formed the group Endangered Catholics, which won political endorsements in an organized protest against the diocese. Those churches are among the ones ordered reopened.

Leaders from three closed parishes demanded March 15 that the diocese immediately unlock the churches, return property and money that it seized when they were closed, and assign priests so that services can resume.

Lennon issued a statement March 15 that confirmed he had received notification of the rulings from Rome, but he declined to provide details about the legal orders and made no commitment to reopen the churches any time soon. The legal decision was first rumored two weeks ago, but at the time Lennon denied any knowledge of it and then a spokesman said later he had not opened his mail.

Lennon’s initial orders triggered an open revolt among many Cleveland Catholics. When he conducted the final Masses inside some of the churches, Cleveland police would sit in the pews. At one closing, he was openly mocked when he attempted to defend his actions and say he was “not without sensitivity.”

“I don’t think Lennon understands what hit him,” said Peter Borre, a Catholic activist in Boston who provided legal advice to the Cleveland parishes. “Bishops almost always win.”

Borre said a review he conducted of U.S. church closures over the last 15 years failed to identify a single known case in which a bishop was reversed by the Vatican. Diocese spokesman Robert Tayek did not return calls seeking comment.

Lennon has 60 days to appeal the ruling to the high court of the Vatican.

Lennon had justified the closure orders in 2009 by asserting the churches were financially insolvent, the diocese did not have enough priests to staff the parishes, and that few parishioners actually attended services, other than on Easter and Christmas.