SALT LAKE CITY — For 20-plus years, the LDS Church president has presided, been present and spoken publicly in at least one of the church's biannual general conference sessions.

That may not be the case this fall, given that President Thomas S. Monson, president and prophet of The Church of Jesus Christ of Latter-day Saints, is dealing with incidents related to age. After giving two very brief addresses in the previous April 2017 conference and then being hospitalized briefly afterward, he may not speak at the October 2017 general conference and may not attend.

For newer or younger members of the Mormon faith, a general conference without the church president's attendance or participation may be something new. Older, more tenured Latter-day Saints will remember frequent times when general conference occurred without the church president speaking — or perhaps even present for any session.

Since 1994, the three most recent church presidents — President Monson, President Gordon B. Hinckley and President Howard W. Hunter — all had attended at least one session of general conference and given one talk during each conference during their tenures of presiding.

A mainstay at general conferences since being named a church apostle more than 50 years ago, President Monson may not be able to attend. A May 23, 2017, church statement said “because of limitations incident to his age, President Monson is no longer attending meetings at the church office on a regular basis.”

Similar health challenges faced other presidents of the church, including President David O. McKay in the late 1960s, President Spencer W. Kimball in the 1980s, and President Ezra Taft Benson in the late 1980s and ealy 1990s.

The ability and availability of aging LDS Church leaders has been addressed before with messages assuring members of the church’s sustained leadership, despite deteriorating health or diminishing capabilities of an aged president-prophet.

President Russell M. Nelson, president of the Quorum of the Twelve Apostles, spoke on the church’s system of seniority that brings older men to the office of president of the church, providing maturity and experience to the position.

“The church today has been organized by the Lord himself,” he said in his October 2014 address. “He has put in place a remarkable system of governance that provides redundancy and backup. That system provides for prophetic leadership even when the inevitable illnesses and incapacities may come with advancing age.”

He referred to 1983 and 1994 conference addresses on a similar theme by President Hinckley, who at the two times was serving as a First Presidency counselor to a pair of ailing church presidents, Presidents Kimball and Benson, respectively.

“It is important,” said President Nelson, quoting President Hinckley’s 1994 message, “that there be no doubts or concerns about the governance of the church and the exercise of the prophetic gifts, including the right to inspiration and revelation in administering the affairs and programs of the church, when the president may be ill or is not able to function fully.

“The First Presidency and the Council of the Twelve Apostles, called and ordained to hold the keys of the priesthood, have the authority and responsibility to govern the church, to administer its ordinances, to expound its doctrine, and to establish and maintain its practices.”

He continued quoting the 1994 address: “When the president is ill or not able to function fully in all of the duties of his office, his two counselors together comprise a Quorum of the First Presidency. They carry on with the day-to-day work of the presidency. … But any major questions of policy, procedure, programs or doctrine are considered deliberately and prayerfully by the First Presidency and the Twelve together.”

President Monson addressed the issue of age and capacity himself four years ago, in a Church News piece he penned reflecting on five years of service as LDS Church president and a half-century as a member of the church’s Quorum of the Twelve Apostles.

“Age eventually takes its toll on all of us,” he wrote, adding “despite any health challenges that may come to us, despite any weakness in body or mind, we serve to the best of our ability.

“The system set up for the Council of the First Presidency and Quorum of the Twelve (Apostles) assures that it will always be in good hands and that, come what may, there is no need to worry or to fear. Our Savior, Jesus Christ, whom we follow, whom we worship, and whom we serve, is ever at the helm.”

Following is a brief but closer look at the eight most recent of the LDS Church's 16 presidents and the general conferences during their tenures when they didn't speak or had their prepared messages read by another, or didn't attend any session of a particular conference.

• President David O. McKay (April 9, 1951, through Jan. 18, 1970) suffered deteriorating health in the mid-1960s; for the first time in his tenure, the 91-year church president missed attending October 1964 general conference, on the advise of his physician.

At that conference, President McKay’s two messages were read by sons Robert R. McKay and David Lawrence McKay, the latter serving as a member of the church’s general superintendency of the Sunday School organization since 1949, including as general superintendent from 1966 to 1971.

Such a pattern was set for the remainder of general conferences through the end of the 1960s; most of President McKay’s later conference messages were read by one of his two sons, whether the president-prophet was in attendance for all sessions in a single conference, some of the sessions or none at all. In some conferences during that time, two talks from President McKay were read aloud; other conferences had three.

After his initial absence in 1964, President McKay did return to the Tabernacle’s pulpit for three conferences, speaking in early sessions in the October 1965, April 1966 and October 1966 general conferences. In fact, the 93-year-old church president spoke for 40 minutes in an opening session on Friday morning, Sept. 30, 1966; it would be the last time President McKay spoke himself in general conference.

But even in those conferences where President McKay spoke in one session, his sons still read his additional talks in subsequent sessions.

• President Joseph Fielding Smith (Jan. 23, 1970, to July 2, 1972), at age 93, was the oldest man to be sustained as LDS Church president. He attended and spoke at the five general conferences held while he served, before passing away at age of 95.

• President Harold B. Lee (July 7, 1972, to Dec. 26, 1973) attended and spoke at the three general conferences — October 1972, April 1973 and October 1973 — during his tenure as church president before he passed away at age 74.

• President Spencer W. Kimball (Dec. 30, 1973, to Nov. 5, 1985) first missed a couple of conference sessions in April 1980, but it wasn’t for reasons related to health or age.

After speaking in the Saturday morning opening session of that general conference, President Kimball flew to New York and participated in the Sunday morning session via satellite link from first the Peter Whitmer Sr. farmhouse in Fayette, New York, and then the church’s nearby meetinghouse.

The Fayette broadcast originated from the site where the church was organized 150 years previous, with President Kimball introducing a world proclamation commemorating the anniversary and then dedicating the Fayette facilities.

President Kimball missed the entire October 1981 general conference, being hospitalized with some complications following cranial surgery on Sept. 5, 1981, to remove fluid and scar tissue beneath his skull.

From that point until 1985, President Kimball’s attendance at general conference was sporadic — sometimes attending a session or two or even three, and sometimes not attending any session. His personal secretary, D. Arthur Haycock, read the last two conference talks attributed to President Kimball — one each in the April and October 1982 general conferences.

During the Sunday afternoon session of the April 1982 general conference, President Kimball unexpectedly rose to offer a brief, three-sentence closing message:

“My beloved brothers and sisters, this is a great experience for me. I have waited for this day and hoped for it and believed for it. I have a great love for the people of this church, and gratitude for the love expressed by them and by all the people of these valleys. So as I express that love for you and for the memory of the great experiences I’ve had with you, I bear my testimony: This work is divine, the Lord is at the helm, the church is true, and all is well. God bless you, brothers and sisters, I pray in the name of the Lord Jesus Christ, amen.

In both general conferences in 1985, the 90-year-old President Kimball attended all four general sessions— the first time since April 1981. But he did not speak in either one. The April 1985 general conference priesthood session featured a 12-minute montage of talk excerpts from President Kimball.

• President Ezra Taft Benson (Nov. 10, 1985, to May 30, 1994), after suffering a heart attack in mid-October 1987, spoke in both the opening and priesthood sessions of the subsequent general conference in April 1988. However, President Hinckley, then first counselor in the church’s First Presidency, read President Benson's closing remarks in the Sunday afternoon session, and President Benson wouldn’t speak himself in general conference again.

While President McKay used his sons to convey conference messages, President Benson’s counselors continued to do the same for him in subsequent years as poor health first limited his general conference attendance and then ultimately precluded it.

President Benson’s well-known “Beware of Pride” conference talk was actually read by President Hinckley in the opening session of the April 1989 general conference, with President Monson, then the second counselor in the First Presidency, reading the closing-session remarks. The two continued to speak on behalf of President Benson in subsequent conferences, reading talks attributed to him, paying tribute to him or sharing previous talks or quotes from him.

In October 1990 and at the age of 91, he was hospitalized in satisfactory condition with a subdural hematoma and gastrointestinal bleeding, missing general conference for the first time in his presidential tenure. He returned to attending all or part of the morning sessions of general conferences in 1991 and April 1992, but did not attend sessions again beginning in October 1992 until his death.

• President Howard W. Hunter (June 5, 1994, to March 3, 1995) was sustained and spoke at the October 1994 general conference — the only general conference over which he presided in his brief, nine-month tenure as president-prophet of the LDS Church.

• President Gordon B. Hinckley (March 12, 1995, to Jan. 27, 2008) attended and spoke at the 26 general conferences held during the 13 years while he presided over the church. When he passed away at age 97, he was the oldest to have served as the church's president.

• President Thomas S. Monson (Feb. 3, 2008, to present) has spoken at every general conference to this point during his tenure as LDS Church president.