January: President Barack Obama is sworn in for his second term after winning re-election in November 2012.
February: The Baltimore Ravens won the Super Bowl, beating the San Francisco 49ers 34-31. But it wasn't the game itself that people were talking about the next day -- it was the blackout that caused an unexpected 34-minute break in the game.
February: A video of young men dancing like crazy is uploaded to YouTube and a craze is created. You probably know that craze as the "Harlem Shake." It has since been parodied countless times all over the world.
February: Pope Benedict XVI stuns the world by announcing plans to resign at the end of February "because of advanced age." He was the first pope to resign in more than 600 years.
March: Cardinal Jorge Mario Bergoglio is elected pope. He immediately begins breaking with some traditions, becoming the first pope to pick the name Francis, beginning his first address as pope by asking the people in St. Peter's Square to pray for him and insisting on going back to his hotel to pay his hotel bill himself the following day. He continued turning heads his first several months as pontiff by making a point to live simply, embracing the poor, opening up the Vatican's finances to scrutiny and saying the church spends too much time talking about social issues like homosexuality and abortion.
April: Two homemade bombs explode at the Boston Marathon, killing three spectators and injuring several others. Two days later, police released photos of two suspected bombers, later identified as brothers Tamerlan and Dzhokhar Tsarnaev. The next day, the Tsarnaev brothers led a chase that began with the shooting death of a police officer and ended up shutting down the city for most of a day. Tamerlan Tsarnaev was killed in a shootout with police early in the chase, and Dzhokhar Tsarnaev was found badly injured and hiding in a boat that was parked in a front yard hours later.
May: Three women who had all been missing for more than 10 years are discovered in a house in Cleveland, Ohio, after one of the women manages to get to the front door and yell to a neighbor. Amanda Berry, Gina DeJesus and Michelle Knight had all disappeared separately between 2002 and 2004. Their captor, Ariel Castro, hung himself in a jail cell a few months later.
May: An Arizona jury finds Jodi Arias guilty of murdering her ex-boyfriend, Travis Alexander. Alexander was found dead in 2008; he had been stabbed 29 times, his neck was slit from ear to ear and he was shot in the face. The jury reached a stalemate in the sentencing phase, which means another jury will decide whether Arias will be sentenced to life in prison or the death penalty. The second sentencing phase has yet to occur.
June: Advocates of same-sex marriage celebrated after the U.S. Supreme Court overturned provisions in the Defense of Marriage Act that prevented the federal government from recognizing same-sex marriages and struck down an appeal of a lower court's decision to overturn California's Proposition 8, which defined marriage as being between one man and one woman in that state's constitution.
June: Authorities charged former New England Patriots tight end Aaron Hernandez with first-degree murder hours after police arrested him and the NFL team that once gave him a $40 million contract dropped him from its roster. Hernandez is accused in the shooting death of Odin Lloyd, a semi-pro football player whose body was found in an industrial park area less than a mile from Hernandez's home.
June: Actor James Gandolfini, best known for his portrayal of mob boss Tony Soprano on HBO's "The Sopranos," died from a heart attack while vacationing in Rome, Italy.
July: Cory Monteith, who played Finn on the hit TV show "Glee," is found dead in a hotel room. His cause of death was ruled to be a toxic mix of drugs.
July: George Zimmerman is acquitted of murder in the death of Trayvon Martin. In February 2012, Zimmerman, a neighborhood watch captain, called 911 to report a suspicious looking person when he saw the 17-year-old Martin walking to his father's fiancee's home late one night. Zimmerman never denied that he confronted and ultimately shot Martin, but always maintained he did so in self-defense after the confrontation turned physical. The verdict divided the country and sparked protests in several cities.
July: Catherine, Duchess of Cambridge, gave birth to Prince George, the first child of Catherine and Prince William and third in line to the British throne.
August: California teen Hannah Anderson disappeared after cheerleading practice on the afternoon of Aug. 3. The next day, the bodies of her mother, Christina Anderson, and 8-year-old brother, Ethan, were found in family friend James DiMaggio's burned house. That sparked a nationwide search for DiMaggio, who was believed to be holding Anderson. The two were found in Idaho a week later heading into a wilderness area on horseback. DiMaggio was fatally shot, and Anderson was reunited with her father.
September: Apple unveiled two new versions of the iPhone, the iPhone 5S and the iPhone 5C. The 5S was the higher-end version, with features including a fingerprint recognition sensor. The 5C was a cheaper version of the phone. The company sold a record 9 million phones the first weekend the two new models were available.
September: Military contractor Aaron Alexis shoots and kills 12 people at the Washington Navy Yard in Washington, D.C. The gunman would ultimately be shot and killed by police about 30 minutes after the shooting began. Eight other people were also injured in the attack.
September: Syria agreed to an internationally-monitored process to destroy its chemical weapons, which are believed to be responsible for some of the deadliest attacks in Syria's ongoing civil war. But the destruction of chemical weapons doesn't mean the violence is coming to an end -- indeed, attacks are still a daily occurrence. In the past three years, the war has killed more than 100,000 people, including more than 11,000 children, according to the United Nations and the Oxford Research Group.
October: The House and Senate reach a deadlock on a budget funding bill after a group of Republican representatives refuses to pass a budget bill without a provision to delay the Affordable Care Act for a year and the Democrats in control of the Senate refuse to approve the bill with the provision. National parks closed, federal employees were either furloughed or forced to work without a paycheck until the shutdown ended (although all employees were ultimately paid for the time retroactively), jobs of government contractors were threatened and even the National Zoo's panda cam went dark. A budget bill that didn't delay the Affordable Care Act's implementation was passed and signed into law 16 days later, ending the shutdown.
October: Three years after the passage of the Affordable Care Act, state and federal health care exchanges meant to let people buy health care before the individual mandate to buy insurance kicks in in 2014 went online. But there were quickly reports of people having problems with the Affordable Care Act website, which were initially described as "glitches" but later acknowledged to be more serious problems. Other issues have plagued the rollout of the law -- including some people getting letters saying their existing plans were being canceled despite a promise from the president that people who liked their coverage could keep it -- but problems with the website and low early sign-up numbers that were largely blamed on the site have so far dominated the conversation.
November: A gunman opened fire in Los Angeles International Airport, killing Transportation Security Administration officer Gerardo Hernandez and wounded two other agents and a passenger in what appeared to be an orchestrated assault on members of the federal agency responsible for airport security. Suspect Paul Ciancia was shot by officers at the scene and taken into custody.
November: Typhoon Haiyan devastates the Philippines. Early death tolls fluctuated a great deal, but five weeks after the disaster, agencies were reporting more than 6,000 dead, more than 27,000 injured and 3.9 million displaced from their homes.
November: Actor Paul Walker, who was best known for his work in the "Fast and Furious" franchise, is killed in a car crash.
December: North Korea figured prominently in a number of stories in 2013 -- questions of whether the country would fire missiles after making threats in March and April, holding and then releasing 85-year-old American Merrill Newman, continuing to hold American Kenneth Bae, playing host to former NBA star Dennis Rodman -- but perhaps the biggest story to come out of North Korea this year was news that leader Kim Jong Un had his uncle, Jang Song Taek, very publicly cast out of the ruling party and then executed. Jang was believed to be the second most powerful man in North Korea.
December: Nelson Mandela, a leader in South Africa's fight against apartheid and his country's first black president, dies after a long illness. He was 95.
Actress Tori Spelling recently spoke publically about her husband and fellow actor Dean McDermott's affair. But he's not the first celebrity to get in hot water over extramarital activities. Check out this list of high-profile celebrity affairs.