The sun never sets on James Keyes’s empire.

Its iconic red-green-and-white marquee rises at 28,000 locations in 18 countries. That puts Mr. Keyes, CEO of 7-Eleven, in charge of the world’s largest chain of convenience retail stores. Yesterday, he extended his domain to Manhattan with the opening of his newest franchise.

The crowds that flocked to Indian born Jimmy Solanki’s store at 107 E. 23rd St. were large, but still only a fraction of the 6 million Americans who give their custom every day to some 6,000 7-Eleven stores around the country. The 22,000 foreign franchises, the lion’s share of which are in Japan, attract millions more people.

The opening of Mr. Solanki’s store represents a resurrection of sorts for 7-Eleven. It had shuttered its New York stores some years ago during a particularly bleak time for the enterprise, which started in Dallas in 1927 selling blocks of ice and dry goods. In 1991, the Japanese retailer Ito-Yokado and Seven-Eleven Japan acquired a majority interest in the company.

But yesterday’s event also had special significance for Mr. Keyes. It was as a student at Columbia’s business school that he made his first foray into the American corporate world through an internship with Gulf Oil. The company, impressed by his combination of brio and brains, hired him after he received his MBA.

“My life has been a series of very good fortunes,” Mr. Keyes said.

One of those fortunes was his friendship at Columbia with Mark Weill, son of the financial titan Sanford Weill. The older Mr. Weill, and his wife, Joan, became mentors.

As they chatted at his graduation with his mother, Dorothy, and brother Roger, it occurred to Mr. Keyes that Mr. Weill and he had something in common. Mr. Weill came from a modest Brooklyn background, and started his stellar career as a runner on Wall Street. Mr. Keyes came from a humble background, too, growing up as the youngest of six children in a shack in Grafton, Mass., that had no electricity or running water. His parents were factory workers, and his father died when Mr. Keyes was 12.

“I’ve never forgotten those days,” he said. “The adversity prepared me to face anything that came my way.”

Mr. Keyes had to work in a factory and as a truck driver to pay his tuition at Holy Cross College. In his junior year, he won a place at the University of London.

“That was the beginning of a lifetime of rich experiences for me,” he said. “My roommate was Pakistani. My friends were Britons and other nationalities. London was about understanding the rest of the world.”

Although he couldn’t have known it at the time, his London sojourn was a precursor to a business life in which understanding foreign cultures was in valuable. As he expanded 7-Eleven – which has annual sales of $41 billion – around the world, Mr. Keyes realized that business was about more than numbers; it was really about people.

His acuity saw him course through managerial positions at Gulf Oil, Chevron, and Citgo. He was hired by 7-Eleven, where his management skills propelled him through a lethargic bureaucracy. In 2000, barely 14 years after joining the company, Mr. Keyes became CEO.

So what’s it like to be CEO of the world’s biggest retail-store chain?

“There’s a difference between being a manager and a leader,” Mr. Keyes said. “As a leader, people look to you to guide them and also inspire them. Perhaps my own life story has some impact on my colleagues. But there’s a fine line between confidence and arrogance. I like to think that I’ve stayed on the right side of that line.”

His stewardship of 7-Eleven has also been salutary for a company that faced Chapter 11 barely a decade ago. Mr. Keyes increased investment in technology. Now computerization can move items much faster at stores, and also gives owners the ability to customize inventories to meet clients’ needs.