Hinckley, the 15th president of The Church of Jesus Christ of Latter-day Saints, died of complications arising from old age, church spokesman Mike Otterson said.

"His life was a true testament of service, and he had an abiding love for others," said U.S. Sen. Orrin Hatch, a Utah Republican and fellow Mormon. "His wit, wisdom, and exemplary leadership will be missed by not only members of our faith, but by people of all faiths throughout the world."

By unfailing tradition, at a church president's death, the church's most senior apostle is ordained within days on a unanimous vote of the Council of the Twelve Apostles. The most long-serving apostle now is Thomas S. Monson, 80.

The church presidency is a lifetime position.

Hinckley, a grandson of Mormon pioneers, was president for nearly 13 years. He took over as president and prophet on March 12, 1995 and oversaw one of the greatest periods of expansion in church history.

The number of temples worldwide more than doubled, from 49 to more than 120 and church membership grew from about 9 million to more than 12 million.

The number of Mormons outside the United States surpassed that of American Mormons for the first time since the church, the most successful faith born in the United States, was founded in 1830.

Over the years, Hinckley labored long to burnish the faith's image as a world religion far removed from its peculiar and polygamous roots. Still, during his tenure the Roman Catholic Church, Southern Baptist Convention and United Methodist Church — the three largest U.S. denominations — each declared that Mormon doctrines depart from mainstream Christianity.

"We are not a weird people," Hinckley told Mike Wallace on "60 Minutes" in 1996.

"The more people come to know us, the better they will understand us," Hinckley said in 2005. "We're a little different. We don't smoke. We don't drink. We do things in a little different way. That's not dishonorable. I believe that's to our credit."

Hinckley's grandfather knew church founder Joseph Smith and followed Brigham Young west to the Great Salt Lake Basin.

Born June 23, 1910, in Salt Lake City, Hinckley graduated from the University of Utah with a degree in arts and planned to attend graduate school in journalism. Instead, a church mission took him to the British Isles.

Upon his return, he became executive director of the newly formed Church Radio, Publicity, and Mission Literature Committee at $60 a month. Hinckley always worked for the church, except for a brief stint during World War II as a railroad agent.