While he ultimately went in another direction, “power” is a word that still holds a lot of meaning for us. We’ve always covered the most important and impactful people and companies. We’ve portrayed the ones that used power wisely—and called for accountability for the ones who used it unwisely. In 1998, our editors created the Most Powerful Women in Business list, to monitor how the drive against gender discrimination was changing where authority rested in the top ranks of Fortune 500 companies.

But our goal, of course, is to track the most powerful companies in the world—and those who lead them, regardless of gender. So this year, we decided to launch a global power ranking for the corporate world. We wanted it to be authoritative, current, and backed up by data.

Our editors set out to answer a simple-sounding but actually complex question: What is power? Is it defined by the profit number on your company’s balance sheet? A splashy job title? Or is it how much you influence others?

Ultimately, we zeroed in on a few factors. Some were quantitative: the size of a business a person oversees; the overall health of the business. Others were more personal, but still measurable: how innovative the leader’s work is, their career trajectory, and the size of the impact they’re making on others.

From there, our editors debated—all the way through the election. It became clear from all the criteria that there could only be one person in the top spot this year: Elon Musk. The leader of Tesla, X, and SpaceX is now a central force in the incoming Trump administration, where he will oversee efficiency, weigh in heavily on AI, and likely see all his businesses significantly benefit, to the detriment of competitors like Sam Altman of OpenAI and Jeff Bezos of Blue Origin. As Jessica Mathews explains in “Welcome to Elontown, USA: an unlikely Texas home base for Musk’s business empire”, given his control of X, and the prominence of his tweets (even on feeds of those who don’t follow his account), his influence is unmatched.

Check out the list here, and write in to let us know how we did: feedback@fortune.com. And if you’re looking for ­alternative-to-Elon programming, read Jeremy Kahn’s account of Jensen Huang’s rise at Nvidia (“60 direct reports, but no 1-on-1 meetings: How an unconventional leadership style helped Jensen Huang of Nvidia become one of the most powerful people in business”) and Sharon Goldman’s story about Mark Zuckerberg’s AI-driven reinvention of Meta (“How Mark Zuckerberg went all-in to make Meta a major AI player and threaten OpenAI’s dominance”).

What will a second Trump presidency look like, with Elon and a whole new cabinet helping him run the show? For that, we turned to a truly insightful expert on the topic: Ian Bremmer, founder of the political risk consulting firm Eurasia Group. Bremmer penned our digital cover story (and magazine essay, “What global business leaders need to know about Trump 2.0”) on what business leaders can expect and the economic impact the 47th president will likely have.

The big takeaway: At a time when so many powerful companies are truly global, America’s relationships with China, Europe, the Middle East, and the rest of the world matter more than ever. And whether they change for better or worse, they’re almost certain to change dramatically, and in short order.

This article appears in the December 2024/January 2025 issue of Fortune with the headline “What is power?“