Lawrence Wright was reluctant to adapt “The Looming Tower,” his Pulitzer Prize-winning history of Al Qaeda and the run-up to 9/11. But it wasn’t lost on him that the number of deals for scripted series was rapidly increasing each year — a development that went along with the sudden rise of the streaming industry.

“It became clear to me something’s going to be done, whether it’s my book or some other entity using the book without actually acknowledging it,” Mr. Wright said. “I decided I better take control of this.”

Once he became serious about the project, he did not imagine it would end up at Hulu. This was in 2015, two years before Hulu won eight Emmy Awards for “The Handmaid’s Tale,” back when it was best known as a platform where viewers could stream episodes of network television shows.

Mr. Wright developed the idea with the screenwriter Dan Futterman, who had written the scripts for “Capote” and “Foxcatcher,” and the filmmaker Alex Gibney, who had directed a documentary based on Mr. Wright’s 2013 book, “Going Clear: Scientology, Hollywood and the Prison of Belief.”

Once they had their pitch honed, they approached HBO, Netflix and Amazon, each of which had proved able to make the kind of ambitious series they were envisioning. As a courtesy, they sent word to Hulu.

Craig Erwich, the head of content at Hulu, read “The Looming Tower” soon after it was published in 2006. He even asked for a meeting with Mr. Wright in 2007, when he was an executive at Fox. Eight years later, he was a contender.

“I got a phone call from the reps,” Mr. Erwich said, “and they were like, ‘Are you aware of this book “The Looming Tower”? And I was like, ‘Am I!’”

When Mr. Wright, Mr. Futterman and Mr. Gibney entered Hulu’s headquarters in Santa Monica, Calif., their expectations were not high. “It was a meeting we considered discretionary,“ said Mr. Wright, 70, who goes by Larry.

The author and his two collaborators sat in a tiny conference room with Mr. Erwich and Beatrice Springborn, Hulu’s head of original programming. During the meeting Mr. Erwich did not hold back his enthusiasm. “He was like a fanboy of Larry’s,” Mr. Futterman recalled.

The Hulu executives surprised the “Looming Tower” team by offering them the works. A straight-to-series order, with no lengthy development process? Done. A promise not to buckle under pressure from the federal agencies who may not like how the series would portray them? Done. The biggest dollar commitment? Done.

The conversation left Mr. Wright and his collaborators slightly dazed. “We walked out of that meeting and said, ‘Are we really doing this? Are we reallygoing to do Hulu?’” Mr. Wright said.

They ended up at a nearby Italian restaurant. Seated at a sidewalk table in the evening light, Mr. Wright and Mr. Gibney ordered martinis, Mr. Futterman had a Peroni, and they talked it over. “We were like, ‘Hulu? Is it growing? Is it not growing?’” Mr. Futterman recalled. “We talked about whether this was a mistake or not.”

They eventually decided that — although Hulu did not have the prestige of HBO, the subscriber base of Netflix or the global might of Amazon — it was the right place for their project. Any remaining doubts held by Mr. Wright and his collaborators were dispelled after Hulu rolled out “The Handmaid’s Tale,” which had its premiere last April to critical acclaim on its way to taking the awards for best drama series at the Emmys and the Golden Globes. Ten years after it began, Hulu was a player at last.

“The Looming Tower,” a 10-episode limited series that stars Jeff Daniels and Peter Sarsgaard, makes its debut on Wednesday. Hulu will follow it up by releasing the second season of “The Handmaid’s Tale” in April and unveiling another big production, “Castle Rock,” a horror anthology series from J. J. Abrams and Stephen King, in the summer.

Unlike Netflix, Hulu is available only in the United States. It has 17 million subscribers, a figure dwarfed by Netflix’s 52.8 million United States subscribers out of more than 100 million worldwide.

Even with the awards and media attention it has received lately, Hulu is heading toward a future clouded with uncertainty, thanks to a tricky corporate structure and the merger mania that has taken hold of the media and entertainment industries. The company has four owners: The Walt Disney Company (30 percent), 21st Century Fox (30 percent), Comcast (30 percent) and Time Warner (10 percent). If Disney’s pending $52.4 billion acquisition of most of 21st Century Fox wins governmental approval, as is expected, Disney will own 60 percent of Hulu.

The Disney-Fox deal raises the question of what will happen to Hulu, given that Disney is already developing two streaming services. Another potential issue is whether or not two of Hulu’s owners — Disney, which owns ABC, and Comcast, which owns NBC Universal — will be able to play nicely with each other after they become owners with uneven stakes in the platform.

“It’s incredibly awkward,” said Rich Greenfield, a media analyst at BTIG, a global financial services firm. “The question is which way it goes: Does Comcast buy out Disney? Or does Disney buy out Comcast?”

The corporate uncertainties have come to Hulu at a time of mounting losses: It lost $920 million in 2017, according to BTIG, which projects that the business will lose $1.67 billion this year. Hulu is also facing more intense competition than ever as its rivals disrupt the entertainment industry by handing out big checks. In recent months, Netflix has signed the producers Shonda Rhimes and Ryan Murphy to nine-figure deals; Amazon has pledged more than $200 million toward a “Lord of the Rings”series; and Apple, a newcomer in the field, is shelling out hundreds of millions to create original programming of its own.

The outlook is not all bleak. According to Peter Rice, the president of 21st Century Fox, Hulu had more subscriber growth domestically than Netflix in the last two quarters of 2017. And this month, Disney signaled its commitment when its chief strategy officer, Kevin Mayer, suggested that the other streaming services now in the works at Disney would not get in Hulu’s way.

“We’re very much in support of growing Hulu,” Mr. Mayer said at Recode’s Code Media conference. “It takes an investment, for sure. We’re happy to undertake that investment for the outcome, which we know is going to happen. It’s going to be a big, profitable service.”

Hulu has tried to match its rivals in courting talent aggressively. In addition to greenlighting “The Looming Tower” and “Castle Rock,” the company made a deal with George Clooney for a six-episode adaptation of “Catch-22”; signed Jason Blum, a producer of “Get Out,” for a monthly horror anthology series; brought aboard Beau Willimon, the creator of “House of Cards,” for a series starring Sean Penn about human colonization of Mars; and arranged for a reboot of the popular 1990s cartoon “Animaniacs” with Steven Spielberg and his Amblin Entertainment production company.

Hulu has also built up its catalog by gaining the rights to shows like “30 Rock,” “The Golden Girls” and “This Is Us.” Its recent purchase of the 15-season library of the NBC medical drama “ER” — which had not appeared on any streaming platform since it went off the air in 2009 — prompted think pieces about the show’s surprising popularity in 2018. Hulu’s moves extended to the executive realm last May, when it hired Joel Stillermanaway from AMC, where he was head of programming, and made him its chief of content.

“Beginning last year, we said this was a time for Hulu to really grow up and be aggressive and be much more offensive in its approach, rather than being defensive,” Randy Freer, the chief executive of Hulu, said.

The company has been fighting its way to prominence ever since it began as an answer to YouTube in 2007.

“Hulu really started as, and has been for the better part of a decade, a hedge,” Mr. Freer said. “It started as a hedge against YouTube — they were going to dominate digital video. Then it was a hedge against Netflix — you didn’t want one buyer of content.”

Mr. Futterman, the screenwriter, said Hulu had won “The Looming Tower” partly because of its guarantee of a speedy development, which appealed to him after his recent dealings with HBO.

Mr. Futterman — who was an executive producer, along with his wife, Anya Epstein, of HBO’s “In Treatment” — said he had grown frustrated by the cable network after it tied up projects he had put together with Ms. Epstein, including a stalled adaptation of the Jennifer Egan novel “A Visit from the Goon Squad.”

“I developed two projects with HBO with Anya after ‘In Treatment,’” Mr. Futterman said. “That was one of among about 200 they were developing.” After noting the promises made by Hulu, he added, “What situation would you rather be in?”

To Mr. Daniels, the Emmy-winning actor who plays the F.B.I. agent John O’Neill in “The Looming Tower,” Hulu is playing in the same league as its chief rivals. “The money feels the same. The production value feels the same,” Mr. Daniels said. “You got all the trucks that a big movie does. Somebody’s spending money on this. We’re filming in, what, four or five countries? That’s not cheap.”