For Jehovah’s Witnesses, Brooklyn Heights was until recently the equivalent of Vatican City for Catholics.

Brooklyn—“the borough of churches”—arguably has no congregation with a more noticeable presence than the Witnesses. The Watch Tower Bible and Tract Society of Pennsylvania, the governing body of the Jehovah’s Witnesses, built its headquarters at 25-30 Columbia Heights, and it is there to greet any visitor driving over the Brooklyn Bridge. The pamphlets its missionaries hand out door to door were printed along the waterfront, put on ships in Brooklyn’s port and sent all around the world.

That was another time, however, and the Jehovah’s Witnesses are going the way of the Dodgers and leaving Brooklyn for good. A decade’s long plan to move upstate is nearly complete, and the Watch Tower Society is listing the last of its holdings for sale.

“We feel that we’re leaving Brooklyn with our heads held high,” said Richard Devine, a spokesman for the Watch Tower Society. “We wish everybody the best as we leave. We’ve always enjoyed working with our neighbors in Brooklyn.”

The Witnesses are the ultimate real estate winners as far as being shrewd landlords who held onto property and then sold the bulk of its portfolio during the borough’s boom. For the last 10 years, the church has been shedding its real estate assets—and in the process they’ve pocketed hundreds of millions of dollars.

It’s true, the church faced criticism for not using any of their profits for community investment, as well as for benefiting from upzonings originally intended for nonprofit use—but others have countered that the Witnesses extremely positive influence over the last 100 years, preserving parts of Brooklyn from falling into urban decay.

“They were a force for good,” said Timothy King, the managing partner of Downtown Brooklyn-based CPEX Real Estate. “The Witnesses never spared any expense maintaining their properties. I think it’s part of their lifestyle. They try to do everything they ever did the best way possible.”

Their buildings have stood out for their location, their quality and their ability to convert with relative ease. At one point, the Witnesses’ Brooklyn real estate empire totaled 4.5 million square feet that spanned 30 buildings, such as the Watchtower Buildings and the Hotel Bossert—making them one of the major players in New York real estate.

But the Watch Tower Society only has nine properties left and has made somewhere in the ballpark of $1.25 billion through sales since 2004, according to a Commercial Observer review of their transactions.

It would be hard to name too many organizations that have as big an impact in the borough, real estate–wise.

While Jehovah’s Witnesses are a little more tight-lipped with outsiders than other sects of Christianity tend to be, their basic beliefs involve a single God, and that Jesus Christ was his son. Dwight Eisenhower was raised as a Jehovah’s Witness before converting to Presbyterianism, and tennis stars Venus and Serena Williams are two of the 8.2 million active Jehovah’s Witnesses. The late-pop star Prince, who converted to the religion in 2001, did not receive hip surgery because it required a blood transfusion—something the religion forbids.

There are varying reasons for how and why the Witnesses wound up in Brooklyn. The Watch Tower Society was established in the 1880s in Pittsburgh by Charles Taze Russell, who formed the Jehovah’s Witnesses roughly a decade earlier.

John Manbeck, a Brooklyn historian, told CO via email that the growing religion was looking for a port city around the early 20th century. Brooklyn, particularly the waterfront where no one wanted to live at that point, was ripe with industrial development and had access to active shipyards.

The Watch Tower Society in 1909 bought the four-story 124 Columbia Heights in Brooklyn Heights as a residence for its leaders and 13-17 Hicks Street for its main church. (The Witnesses rebuilt 124 Columbia Heights in 1927 as a dormitory building. It sold this April for $105 million to a company connected to Florida Panthers hockey team owner Vincent Viola.)

The Witnesses keep their business dealings insular, choosing not to work with outside companies, said Christopher Havens, a Citi Habitats broker who has worked in Brooklyn for 30 years. Cooks affiliated with the Watch Tower Society would make meals for workers in the printing factories, and their own glassmakers replaced windows, as need arose.

That sort of self-sufficiency served it well in its dealings. Watch Tower Society built 10 of the 30 buildings it owned over its century in Brooklyn, according to Devine. While they kept a closed-door policy in many respects, the Witnesses relied mostly on outside contractors for all of their construction until the 1960s, he added, before the Witnesses switched to having outside companies erect simply the shell and the Watch Tower Society building out the interiors. Any sort of interior or exterior renovation was also done in house by congregants.

The Witnesses became real estate players in the 1920s with the construction of 124 Columbia Heights but really went on an acquisition frenzy in the 1960s and 1970s when values began to decrease as crime spiked and New Yorkers began leaving the city, said Devine. “We needed facilities,” he said. “They were available but in terrible, terrible, terrible condition.”

The real estate structure of the Watch Tower Society resembles more closely a public authority than a Fortune 500 company. The Witnesses’ real estate policies are set by a body of high-ranking officials in the religion who give the Watch Tower Society’s head of real estate, Daniel Rice, guidance on what to do, Devine explained. All transactions have to be approved by the board, which meets regularly, in order to close.

By 1999, there were 3,400 Jehovah’s Witnesses living and volunteering for the Watch Tower Society in Brooklyn Heights and the surrounding neighborhoods, according to Devine. (It’s tough to determine how much real estate the Witnesses occupy around the globe, Devine said. The Watch Tower Society has branch offices in 80 countries.) However, the once 4.5-million-square-foot Brooklyn empire—mostly residential, office and industrial with one Kingdom Hall house of worship—it had amassed had become, to use Devine’s term, “inefficient,” and printers for what is still one of the world’s largest publishers were not well suited for the buildings because of the size of the machinery.

The Watch Tower Society announced in 2004 that it would begin selling off properties because its printing operations—one of the largest in the world—would be moved to a facility in Wallkill, N.Y. Five years later, it bought a site in Warwick, N.Y., to relocate its headquarters. The new live-work facility sits on a lake (its neighbors are a state park and IBM), is 1.6 million square feet and energy efficient, Devine said. The Watch Tower Society began assuming its offices there last week and will be transitioning into the Hudson Valley facility over the coming months.

Throughout the construction, which dates back to 2009, the Watch Tower Society has staggered the sales of its various commercial and residential buildings in Brooklyn.

Those properties included 360 Furman Street, which was the mother ship for the Witnesses’ printing operations. It was the first property to sell, in 2004, following the decision to phase out of Brooklyn. The building, at the corner of Furman and Joralemon Streets, sold for $205 million that year. New owner RAL Development Services converted the 773,000-square-foot property into 440 condominium units, along with retail space at the base of the building.

“The selling off in a systematic manner worked to their benefit because they set the market,” said King, whose company until recently represented RAL in retail deals at One Brooklyn Bridge Park. “Each sale almost set a record for one [transaction] but then raised the bar for the next one. This was very thoroughly thought out and executed.”

Robert Knakal, the chairman of New York investment sales at Cushman & Wakefield, has done about eight deals with the Watch Tower Society. He said the intermittent sales were necessary because it would have been impossible to unload such a high number of buildings en masse.

One of the next biggest sales came in 2012 when David Bistricer of Clipper Equities and the Chetrit Group bought the Hotel Bossert for $81 million. Last year, they tapped Fën Hoteles to operate it, and the building is slated to open sometime this year.

The 187,200-square-foot property at 98 Montague Street had its own fascinating history; once considered the Waldorf Astoria of Brooklyn and a favorite watering hole for the Brooklyn Dodgers, the hotel had fallen into disrepair by the 1960s.

“The Bossert Hotel, when they bought it, was a mess,” Havens said. “There were hookers there.”

The Watch Tower Society began leasing the property at the corner of Hicks Street in the 1970s, bought it in the 1980s and used it as a place for visiting congregants to stay. Residents consider the purchase a turning point for the 104-year-old structure and the area.

“A lot of people saw [the Witnesses] as a positive influence when they were buying in the 1960s and 1970s when Brooklyn was going in the wrong direction,” Havens told CO.

Part of their real estate success was rooted in the fact that the Witnesses kept their buildings in tip-top shape.

“We view our work as part of our worship,” said Devine, who moved to Brooklyn Heights about 35 years ago to live and work for the Watch Tower Society. “Our buildings, of course, represent our God and our worship. We just took that very, very seriously.”

Asher Abehsera, the co-founder of Brooklyn-based LIVWRK, told CO in March that the five Dumbo buildings he and his partners bought from the Witnesses three years ago were immaculate when they assumed them. LIVWRK, Kushner Companies and RFR Realty paid $375 million for 77 Sands Street, 55 Prospect Street, 81 Prospect Street, 175 Pearl Street and 117 Adams Street. (Disclosure: Kushner Companies Chief Executive Officer Jared Kushner is the publisher of CO.) The trio embarked on a $100 million renovation of the once single-use buildings, renamed Dumbo Heights, into commercial space that would end up getting leased to WeWork, Etsy and Alexis Bittar.

“They were densely populated with people working in a very collaborative environment,” Abehsera, who did not return requests for comment for this story, said of the buildings earlier this year. “They worked there, they ate there and they put in a lot of hours. Really the bones in the building were built originally for a highly, densely populated community space. Now, in a new age, we are reimagining that experience.”

In December 2015, the Watch Tower Society set off a flurry of interest when it listed its former headquarters campus including 25-30 Columbia Heights along with a development site at 85 Jay Street. The properties caught the eye of prominent Manhattan real estate developers including L&L Holding Company and Vornado Realty Trust—two of the firms reported to have shown interest in the properties.

But Kushner Companies and LIVWRK swooped in with Los Angeles-based CIM Group to buy the combined 739,000-square-foot 25-30 Columbia Heights and the adjoining 55 Furman Street for $340 million. (RFR was originally reported to be the third partner, and varying reports have surfaced as to why CIM was brought in instead.) The new owners plan on renovating the building to turn it into new office space, as CO reported earlier this year.

Brooklynites aren’t necessarily lining the sidewalks of Columbia Heights and giving the Witnesses a wholehearted goodbye.

Tucker Reed, the then-president of the Downtown Brooklyn Partnership, penned an op-ed in Crain’s New York Business last December that called on the Witnesses to invest in the area. The heart of the partnership’s issue was that the Witnesses had benefited from augmented property values and the emergence of Brooklyn Bridge Park while not chipping in for public improvements. Reed, who left the partnership in August, called for the Watch Tower Society to donate roughly $50 million from its real estate gains back into Brooklyn.

“Today, as Brooklyn Bridge Park teems with visitors from across the city, Downtown Brooklyn has emerged as the economic engine of the city’s most populous borough, and its land values have risen alongside,” Reed wrote. “But now the Jehovah’s Witnesses are reaping those benefits on their way out the door without giving back to the neighborhood that fueled its fortunes. It’s time to make sure that happens before it’s too late.”

The Watch Tower Society had an agreement with the New York City Department of Parks and Recreation to fund a park at Brooklyn Bridge Park. Devine said the organization’s commitment to finance the park—dubbed Bridge Park 2—has been fulfilled with a $5.5 million contribution, adding that the Witnesses offered at one point to construct it with volunteer labor.

“We understand that people can have various opinions about what their neighbors are doing,” Devine told CO. “The Parks Department has the funds, and they hopefully are going to move forward.”

In a statement to Crain’s earlier this year about the parks contribution, Reed, who did not return a request for comment for this story, said it was a start but not enough.

In total, the Witnesses had saved $368 million in property sales taxes because it is a registered nonprofit, according to a report by the business improvement organization released this February.

Then there’s the matter of 85 Jay Street, which the City Council rezoned in 2004 so the Watch Tower Society could build four structures—of which one would be 222 feet and another would be 195 feet. The planned upzoning, approved by all but one City Council member, was intended for religious and housing uses for the religious organization.

But because the Watch Tower Society put the property up for sale, a for-profit developer will unfairly benefit from the upzoning, some contend.

Whoever buys 85 Jay Street will have the ability to build up to 1 million square feet. David Yassky, the former councilman who represented Brooklyn Heights from 2001 to 2009, said he wished something had been in place to ensure the upzoning would have been bound for only nonprofit use. (He added that he didn’t believe it was the intent of the group to get better zoning conditions only to profit off of those terms.)

“What it shows me is when the city is going to make zoning concessions on the basis of a particular use, that should be written right into the deed so that you don’t have what you have here: A nonprofit is able to get enough of a zoning concession and then turn around and sell it,” said Yassky, now the dean of Pace University’s law school.

Regardless, Yassky said the Witnesses had been a quality neighbor throughout their history in Brooklyn Heights and the surrounding area. While their mission is to spread the word of their beliefs, they were respectful of the surrounding community not to go knocking on every door.

“The witnesses have been over decades a distinctive presence in Brooklyn Heights,” he said. “In some sense, I think a lot of Brooklyn Heights-ers thought it was a neat feature of the neighborhood that it has been a worldwide Mecca for Jehovah’s Witnesses.”