Pope Benedict XVI's announcement that he would resign the papacy on Feb. 28 caught the world by surprise.
While, in this case, the pope's resignation was due to his age and his concern about his ability to fulfill the ministry entrusted to him, reasons for sudden resignations such as Benedict XVI's vary.
Here's a look at some surprising resignations and the circumstances surrounding them.
In November 2012, CIA Director and four-star general David Petraeus resigned from his CIA position after admitting to an extramarital affair.
An Associated Press report said the FBI discovered the relationship by monitoring Petraeus' emails after being alerted that Petraeus biographer Paula Broadwell might have had access to the account.
"After being married for over 37 years, I showed extremely poor judgment by engaging in an extramarital affair," Petraeus said in a letter released to the CIA workforce. "Such behavior is unacceptable, both as a husband and as the leader of an organization such as ours."
In 1939, first lady Eleanor Roosevelt resigned from the Daughters of the American Revolution after the organization wouldn't allow Marian Anderson, an African American, to perform at its Constitution Hall.
"I am afraid that I have never been a very useful member of the Daughters of the American Revolution, so I know it will make very little difference to you whether I resign, or whether I continue to be a member of your organization," Roosevelt wrote. "However, I am in complete disagreement with the attitude taken in refusing Constitution Hall to a great artist. You have set an example which seems to me unfortunate, and I feel obliged to send in to you my resignation. You had an opportunity to lead in an enlightened way and it seems to me that your organization has failed."
Roosevelt then arranged for Anderson to perform on the steps of the Lincoln Memorial, where more than 75,000 people gathered to hear her sing.
Months after rocketing into the public awareness for her role in the 2008 Republican presidential campaign, then-Gov. Sarah Palin of Alaska announced her resignation in July 2009. She said she arrived at her decision in part to protect her family and to escape ethics probes which have drained her family's finances and hurt her ability to govern, a Washington Post article said.
The state of Alaska had spent almost $300,000 investigating ethics complaints against Palin and her staff, the Post reported at the time, while Palin and her husband Todd have spent $500,000 to "set the record straight."
"Every one — all 15 of the ethics complaints have been dismissed. We've won!" Palin said in her resignation speech. "But it hasn't been cheap — the state has wasted thousands of hours of your time and shelled out some two million of YOUR dollars to response to "opposition research. . . I am determined to take the right path for Alaska even though it is unconventional and not so comfortable"
After the 1915 sinking of the Lusitania, Secretary of State William Jennings Bryan and President Woodrow Wilson disagreed over the handling of the crisis, which left 1,201 people dead, leading Bryan to resign from his position in the administration.
According to the U.S. Department of State, Bryan and Wilson disagreed over singling out Germany with a protest note affirming the right of neutrals to transit on the sea, with Bryan insisting that Wilson send a similar note to Britain and Wilson refusing.
When Wilson sent a second note demanding an end to German submarine warfare, Bryan resigned. History.com says Bryan objected to the second note because he believed it could be taken as a precursor to a war declaration.
In a column published March 14, 2012, at The New York Times, Greg Smith, a Goldman Sachs executive director and head of the firm's United States equity derivatives business in Europe, the Middle East and Africa, wrote that he could no longer "in good conscience," stay with the firm.
"I can honestly say that the environment now is as toxic and destructive as I have ever seen it," Smith wrote. "To put the problem in the simplest terms, the interests of the client continue to be sidelined by the way the firm operates and thinks about making money."
Smith wrote that the firm had changed over the years because it changed the way it thought about leadership.
"Leadership used to be about ideas, setting an example and doing the right thing," Smith wrote. "Today, if you make enough money for the firm (and are not currently an ax murderer) you will be promoted into a position of influence."
In December 1936, less than a year after acending to the throne, King Edward VIII informed the government of his decision to abdicate the throne in order to marry divorcee Wallis Simpson.
The decision made Edward the first British monarch to relinquish the throne since 1399, according to The Independent.
"You all know the reasons which have impelled me to renounce the throne," he said in a radio address. "But I want you to understand that in making up my mind I did not forget the country or the empire, which, as Prince of Wales and lately as King, I have for 25 years tried to serve. But you must believe me when I tell you that I have found it impossible to carry the heavy burden of responsibility and to discharge my dueis as king as I would wish to do without the help and support of the woman I love."
Edward's brother was later proclaimed King George VI.
President Richard Nixon resigned in August 1974, after two years of debate over the Watergate scandals, The Washington Post reported at the time.
"By taking this action, I hope that I will have hastened the start of the process of healing which is so desperately needed in America," Nixon said in a television address.
Nixon said his resignation became necessary after he concluded that he no longer had a "strong enough political base in the Congress" to make holding the office to term a possibility.
"I have never been a quitter. To leave office before my term is completed is abhorrent to every instinct in my body. But as President, I must put the interest of America first," Nixon said. "America needs a full-time President and a full-time Congress, particularly at this time with problems we face at home and abroad."
In 1863, two years before Confederate General Robert E. Lee surrendered to Union General Ulysses S. Grant at Appomattox Court House, Lee attempted to resign as commander of the Army of Northern Virginia due to a defeat at Gettysburg, Penn.
"I have been prompted by these reflections more than once since my return from Pennsylvania to propose to your Excellency the propriety of selecting another commander for this army," Lee wrote to Confederate President Jefferson Davis. "No one is more aware than myself of my inability for the duties of my position. I cannot even accomplish what I myself desire . . . I, therefore, in all sincerity, request your Excellency to take measure to supply my place."
History.com — and history itself — shows that Davis refused the request, saying that finding someone more fit to command or more able to keep the confidence of the army, "is to demand an impossibility."
In June 2010, Gen. Stanley McChrystal resigned from his job as U.S. commander in Afghanistan after a Rolling Stone article titled, "The Runaway General," depicted McChrystal and his aides disparaging the president and administration leaders.
In a January 2013 interview on Today, McChrystal said he met President Obama with resignation in hand when he arrived at the White House after the publication of the article. The president accepted the resignation, calling it the "right strategy for our national security."
"I wanted to stay in the job, but I wanted to do what was best for the mission," Chrystal said. "I felt whatever that the president felt was best for the mission was what I needed to do, so I was happy to go with whatever decision that he made."
In November 2011, Penn State fixture and football coach Joe Paterno announced that he would retire from coaching at the end of the football season after defensive coordinator Jerry Sandusky was charged with sexually abusing children.
"For coach Paterno, the greatest coach of any sport really, to go out like this is unfair," senior offensive tackle Chima Okoli
said when Paterno resigned. "He's meant so much more to the university (than football). He's had such a legacy, and this isn't a fitting end."
There is ongoing debate about the situation, how much Paterno was told, and whether or not he had a role in the scandal, according to the Feb. 11 Time article.
Pope Benedict XVI's announcement that he would step down made him the first pope in nearly 600 years to resign from the office, with the last resignation coming in 1415 when Pope Gregory XII stepped down. The last pope to resign willingly was Celestine V In 1294, The Los Angeles Times reported.
In 1415 during Gregory XII's reign, three men were claiming to be pope. Gregory's resignation was undertaken "in order to put to rest strife within the church," CBS News reported.
In 2008, Fidel Castro stepped down as president of Cuba, ending one of the longest tenure as one of the most all-powerful communist heads of state in the world, The New York Times reported at the time.
The official resignation came two years after Castro handed over power temporarily to his brother Raul Castro and a few younger cabinet ministers.
"I will not aspire to neither will I accept — I repeat, I will not aspire to neither will I accept — the position of President of the Council of State and Commander in chief," Castro wrote in a letter. "It would betray my conscience to occupy a responsibility that requires mobility and the total commitment that I am not in the physical condition to offer."
In August 2010, Jet Blue attendant Steven Slater ended his career with the company rather dramatically after arguing with a passenger, getting on the public-address intercom and swearing at those on the flight, grabbing a beer from the beverage cart, pulling the lever to activate the emergency-evacuation chute and sliding away.
He was arrested at his home in Belle Harbor, Queens, and charged with felony counts of criminal mischief and reckless endangerment, The New York Times reported.
A little more than a year later, Slater was sentenced to one year of probation and a $10,000 fine.
In November 2012, Rep. Jesse Jackson Jr., D-Ill., resigned from Congress, citing health reasons but also acknowledging an ongoing federal investigation, USA Today reported at the time.
"Over the past several months, as my health has deteriorated, my ability to serve the constituents of my district has continued to diminish," Jackson said in a letter to House Speaker John Boehner. "I am aware of the ongoing federal investigation into my activities and I am doing my best to address the situation responsibly, cooperate with investigators and accept responsibility for my mistakes, for they are my mistakes and mine alone."
The resignation came a few months after Jackson took a medical leave of absence for "exhaustion."
Jackson reached a plea agreement with prosecutors investigating his alleged misuse of campaign funds on Feb. 8, 2013, a USA Today article said.
At the same time Egyptians took to the polls in December 2012 in a referendum vote on a new constitution, President Mohammed Morsi's vice president, Mahmoud Mekki, announced his resignation. The hurried departure came hours before the polls closed, The Associated Press reported, and could have been linked to Morsi's policies.
"I have realized a while ago that the nature of politics don't suit my professional background as a judge," Mekki said in his resignation letter.
Morsi appointed Mekki to the vice president position in August 2012. According to Daily News Egypt, Mekki returned to Egypt from Kuwait during the protests against former Egyptian President Hosni Mubarak.