After moving Quicken Loans downtown in 2010, Gilbert went on a dazzling real estate buying spree, gobbling up more than 100 properties.

But instead of becoming yet another speculator who sits on empty, rotting properties — or razing buildings for more surface parking — Gilbert deployed capital throughout the central business district, turning around one distressed property after another.

Suddenly, Detroit, the poorest big city in America, had a John Varvatos store selling $1,200 alpaca plaid coats. Last month, Buddy's Pizza, the post-war originator of Detroit-style pizza pies, opened a downtown pizzeria in the Gilbert-owned Madison Building (two years after Angelina Italian Bistro closed, citing Gilbert's rising rents).

Over the past decade, Gilbert the real estate mogul has reshaped downtown.

His employees' desire for outdoor public space to enjoy Detroit is but one reason why there are basketball courts in Cadillac Square.

Gilbert was an early backer of the QLine, buying naming rights for the streetcar and giving his employees passes to boost ridership and cut down on parking congestion.

He even got the operating company for the Detroit newspapers to sell The Detroit News' historic Lafayette Boulevard building to him and then move into his renovated Federal Reserve building on Fort Street and become tenants. Then he bought the long-vacant Detroit Free Press building on Lafayette and is currently renovating that 14-story-tall Albert Kahn-designed hulk.

Quicken Loans and the family of companies (there are literally dozens of them) swelled to a Detroit workforce of 17,000 — more employees downtown than GM, Blue Cross Blue Shield and the Detroit Medical Center combined.

Gilbert's moves bought him great fanfare, adding credibility to a narrative in the national media that Detroit was a comeback city. The likes of JPMorgan Chase CEO Jamie Dimon bought it.

Ford Motor Co. bought the decrepit Michigan Central Station train depot — an unimaginable redevelopment project prior to Gilbert's downtown crusade — as Henry Ford's great-grandson, Bill Ford Jr., follows Gilbert's fundamental belief that innovation will be borne from cities, not sterile suburban office parks.

After largely filling up his main downtown buildings with employees and tenants, Gilbert vowed to go to vertical in a city where a skyscraper hasn't been built since the early 1990s when the One Detroit Center was constructed (Gilbert bought the 43-story tower in 2015).

Politicians rushed to help the billionaire make it happen. Then-Gov. Rick Snyder even crossed his no-new-tax incentives red line to help Gilbert justify breaking ground on a skyscraper at the base of the former J.L. Hudson's department store.

As Gilbert made real estate moves and Quicken Loans scrapped and clawed to be No. 1 in the residential mortgage origination business, the billionaire businessman started moving into other areas of Detroit life.

After Gilbert co-chaired a 2013 task force on blight and testified in federal court about it in Detroit's bankruptcy case, his company's philanthropic arm went looking for solutions to preventing neighborhood blight and destabilization.

The Quicken Loans Community Fund used community groups to hire Detroiters to canvass neighborhoods and educate low-income homeowners about their right to get exempted from paying property taxes — a proactive measure meant to stem the tide of foreclosures running through the county treasurer's office.

And to illustrate just how closely aligned Gilbert's company is with Mayor Mike Duggan's administration, the Quicken Loans Community Fund recently paid a consultant to help the city's building department redesign its notoriously difficult permitting and inspection processes and forms — effectively pulling city bureaucrats into the digital age.

Gilbert also stewed in recent years about the high price of auto insurance.

During an October 2017 interview about the bid he was orchestrating to pitch Amazon on building a second headquarters in Detroit (which Duggan effectively outsourced to Gilbert), Gilbert told Crain's reporters he wanted to reserve a few minutes at the end to discuss auto insurance.

It turned into a 10-minute rant.

Gilbert decried "the predatory plaintiff bar" of personal injury attorneys and "certain parts" of the medical industry that he said work together to "profit enormously and unjustly from this crazy law."

Now, it's not uncommon for businesspeople to have opinions. Even about laws they know little about.

But Gilbert dispatched a team of lobbyists and consultants to the Capitol to engage in a campaign to get the Legislature to eliminate mandatory medical coverage for auto insurance. He threatened a 2020 ballot campaign.

In less than two years, Gilbert did what an army of insurance industry lobbyists had failed to do over a couple of decades, getting the Legislature and governor to bend to his will.

On the Sunday of Memorial Day weekend, two days after lawmakers passed that historic reform, Gilbert suffered a debilitating stroke and has rarely been seen publicly since.

Gilbert's condition and long-term prognosis have been a tightly held secret within his privately held company.

The 57-year-old Gilbert hasn't granted any media interviews. A video message he sent to employees from a rehabilitation center in downtown Chicago leaked out of the company's walls in August, showing a bearded Gilbert praising Quicken Loans workers.

His public absence in Detroit over the past six months has left a question mark for some downtown observers about what the next decade will hold, underscoring how Gilbert has, in many ways, held the full faith and credit of the city's future in his hands.

Or maybe we've held our full faith and credit in Gilbert to propel the city forward.

The lieutenants in Gilbert's business empire insist he's still making major decisions.

Steel beams will come out of ground at the Hudson's site this year, Cullen said, attempting to erase any doubts that Gilbert intends to build an iconic skyscraper at a site that invokes memories of downtown shopping before Hudson's closed in 1983.

An architect was hired for renovation of the Book Tower.

And "post-Dan's stroke," Cullen said, the company's leaders finalized a proposal with New York City developer Stephen Ross to build a University of Michigan innovation center and satellite campus at the one-time jail site.

"There's clear evidence that Dan's commitment and enthusiasm about the city of Detroit remains," Cullen said. "He's still making the big decisions, the big strategic plays."

- Editor's Note: This article has been edited to correct its identification of the most recent skyscraper built in Detroit.