CNN  — 

When the founder of your hotel company is a character on “Batman” and “Mad Men,” you’ve officially crossed over from business to brand.

That founder would be Conrad “Connie” Hilton of the eponymous Hilton hotel brand. Hilton, a Texas native, purchased an existing hotel in the town of Cisco in 1919, starting what would eventually become a multigenerational empire.

Conrad Hilton bought The Mobley (shown here) in Texas and converted it into the first Hilton-branded hotel.

But how do you take a group of hotels and make it into something iconic?

Rather than just being a place to sleep (although the places to sleep are very important), some of these Hilton hotels have hosted celebrities and been responsible for new inventions.

Here are a couple of highlights:

Star power

One way to make a hotel famous is by attracting A-list guests. And one way to attract celebrity guests is by being in Los Angeles.

The Hilton hotels became notorious for throwing huge, celebrity-studded parties to celebrate their hotels.

Greeters personally welcomed guests in the lobby in this photo from the Hilton Dallas.

And there wasn’t just professional mingling at play: Conrad Hilton was married to Zsa Zsa Gabor, while his son Conrad Jr., better known as Nicky, wed an 18-year-old Elizabeth Taylor in 1950.

The Beverly Hilton hotel’s ballroom hosts the Grammy and Golden Globe Awards, which means a reliable crowd of actors, musicians, directors, models and more regularly check in.

In 1999, Angelina Jolie – nominated for her role in the TV movie “Gia” – told the press gathered at the hotel that if she won, she’d jump into the pool. She won, and she followed through on her promise – still wearing her custom Randolph Duke gown.

Professor Reneta McCarthy, senior lecturer at Cornell’s School of Hospitality, credits Hilton for not just launching hotels but for nailing a PR strategy.

“All that publicity and cachet – social media wasn’t around then,” McCarthy says. “You had them constantly in the press. Any time they had a hotel opening, they were inviting all the Hollywood elite.”

And Tinseltown isn’t the only place where stars congregate.

John Lennon and Yoko Ono held one leg of their famous “Bed-In” at the Hilton Amsterdam while on their honeymoon in 1969 (the other part was at the Fairmont in Montreal.)

Later, Lennon wrote the lyrics to “Imagine” on a pad of paper at the Hilton New York.

Innovation

Hilton has quite a few firsts in its history.

The brand claims credit for the first hotel with air-conditioning, the first airport hotel (at San Francisco International Airport) and the onetime record holder for biggest hotel in the world, which at the time was the Waldorf-Astoria in New York City.

But that innovation isn’t always inside a room.

The Caribe Hilton in San Juan, Puerto Rico is credited for being the birthplace of the piña colada.

Staff bartender Ramon “Monchito” Marrero developed the original recipe in 1945, and the piña colada was later adopted as the island’s official cocktail.

Dan Wasiolek is senior equity analyst at Morningstar, a global investment company. He specifically tracks Hilton and other similar hotel brands, as well as online travel booking sites, to keep an eye on the travel industry.

He tells CNN Travel that Hilton was ahead of the game when it came to technology.

“They were early innovators to have digital room keys, an app where you can choose your room, customizable features. They were one of the first ones to heavily go all in on this direct marketing campaign by signing up loyalty members and offering promotions to book direct.”

According to Morningstar, Hilton has 12.5% of all hotel rooms in the United States and 5.2% globally.

Not all gems

Like any company, Hilton has had its share of ideas that didn’t quite endure – the Crystal Pepsis of hospitality, if you will.

Darnoc, an in-house vodka brand whose name was “Conrad” spelled backwards, appeared in some rooms and lobby bars in the 1960s and ’70s before being shelved completely.

Vintage bottles of Darnoc vodka.

Hilton also introduced Lady Hilton, aimed specifically at female solo business travelers, in 1963.

Though the idea didn’t last long, it was clear that Hilton recognized that solo female travelers were about to become a significant demographic.