20 May Edward Snowden, an employee of defence contractor Booz Allen Hamilton at the National Security Agency, arrives in Hong Kong from Hawaii. He carries four laptop computers that enable him to gain access to some of the US government's most highly-classified secrets.
1 June Guardian journalists Glenn Greenwald and Ewen MacAskill and documentary maker Laura Poitras fly from New York to Hong Kong. They meet Snowden in a Kowloon hotel after he identifies himself with a Rubik's cube and begin a week of interviews with their source.
5 June The Guardian publishes its first exclusive based on Snowden's leak, revealing a secret court order showing that the US government had forced the telecoms giant Verizon to hand over the phone records of millions of Americans.
6 June A second story reveals the existence of the previously undisclosed programme Prism, which internal NSA documents claim gives the agency "direct access" to data held by Google, Facebook, Apple and other US internet giants. The tech companies deny that they have set up "back door access" to their systems for the US government.
7 June Barack Obama defends the two programmes, saying they are overseen by the courts and Congress. Insisting that "the right balance" had been struck between security and privacy, he says: "You can't have 100% security, and also then have 100% privacy and zero inconvenience."
The Guardian reports that GCHQ has been able to see user communications data from the American internet companies, because it had access to Prism.
8 June Another of Snowden's leaks reveals the existence of an internal NSA tool – Boundless Informant – that allows it to record and analyse where its data comes from, and raises questions about its repeated assurances to Congress that it cannot keep track of all the surveillance it performs on American communications.
9 June Snowden decides to go public. In a video interview he says: "I have no intention of hiding who I am because I know I have done nothing wrong."
10 June Snowden checks out of his Hong Kong hotel.
12 June Hong Kong's South China Morning Post publishes the first interview with Snowden since he revealed his identity. He says he intends to stay in the city until asked to leave and discloses that the NSA has been hacking into Hong Kong and Chinese computers since 2009.
14 June The Home Office instructs airlines not to allow Snowden to board any flights to the UK.
16 June The Guardian reports that GCHQ intercepted foreign politicians' communications at the 2009 G20 summit.
20 June Top secret documents published by the Guardian show how US judges have signed off on broad orders allowing the NSA to make use of information "inadvertently" collected from domestic US communications without a warrant.
21 June A Guardian exclusive reveals that GCHQ has gained access to the network of cables which carry the world's phone calls and internet traffic and is processing vast streams of sensitive personal information it shares with the NSA. The US files espionage charges against Snowden and requests that Hong Kong detain him for extradition.
23 June Snowden leaves Hong Kong on a flight to Moscow. In a statement, the Hong Kong government says documents submitted by the US did not "fully comply with the legal requirements under Hong Kong law" and it had no legal basis to prevent him leaving. Snowden arrives in Moscow. In a statement, WikiLeaks said it was assisting him, in part by providing adviser Sarah Harrison as an escort, and said he was heading to a democratic country, believed to be Ecuador, "via a safe route".
24 June Journalists board a flight from Moscow to Havana amid reports Snowden is about to board – but he doesn't.
Standing next to Edward Snowden's seat on flight to Cuba. He ain't here. pic.twitter.com/NVRH3Pzved
— max seddon (@maxseddon) June 24, 2013
25 June Barack Obama vows to extradite Snowden while John Kerry, US Secretary of State, urges Russia to hand him over.
25 June Russian foreign minister Sergei Lavrov claims Snowden never crossed the border into Russia. But Putin later says Snowden is at Sheremetyevo airport and is free to leave Russia.
26 June Putin says Snowden will not be extradited to America. He denies that his security services had contacted Snowden.
26 June Ecuador warns that it may take months to decide whether to offer Snowden asylum, pointing out that it took two months to decide whether to do so in the case of Julian Assange.
26 June Hong Kong claims, amid growing Sino-American tensions, that the US got Snowden's middle name wrong in documents submitted for his arrest.
27 June Obama declares he will not spend much geopolitical capital on apprehending Snowden. He also claims that he hasn't spoken to Russia nor China about extradition.
27 June Ecuador maintains its defiant stance, renouncing the Andean Trade Preference Act it has with America. The country also offered the US $23m (£15m) for human rights training.
28 June President Rafael Correa of Ecuador revokes Snowden's safe conduct pass amid irritation that Assange was taking over the role of the Ecuadorean government.
29 June Correa reveals that US vice-president Joe Biden asked him to turn down Snowden's asylum request.
1 July A consular official in Russia reveals that Snowden has applied for asylum there. WikiLeaks later reveal that he has applied for asylum in a further 20 countries, amongst them France, Germany, Ireland, China and Cuba.
1 July Snowden releases a statement through the WikiLeaks website in which he claims that he left Hong Kong because "my freedom and safety were under threat". He says it is hypocritical of Obama to promise no "wheeling and dealing" but then instruct Biden to encourage other nations to deny him asylum.
2 July Snowden retracts his request for Russian asylum after Putin says he must stop "bringing harm" to US interests. Meanwhile Brazil, India, Norway and Poland refuse Snowden asylum, while Ecuador, Austria, Finland, Germany, Ireland, the Netherlands, Norway, Poland, Spain and Switzerland say he has to apply from their countries.
2 July Lon Snowden, Edward Snowden's father, and his father's attorney, Bruce Fein, pen an open letter to Edward Snowden praising him, comparing him to Paul Revere and noting the US supreme court decision that "statelessness is not to be imposed as a punishment for crime".
2 July Bolivia throws its hat into the ring with president Evo Morales declaring on Russian television that he would "shield the denounced".
3 July Morales's plane, en route from Moscow to Bolivia, is forced to land in Vienna after other European countries refused it airspace, suspecting that Snowden was on board. Bolivian vice-president Alvaro Garcia says Morales was "kidnapped by imperialism".
3 July Venezuela, Argentina, Ecuador, Uruguay and Bolivia denounce the treatment of Morales, who was held in Vienna airport for 12 hours while his plane was searched for Snowden. Bolivia files a complaint at the UN.
3 July UN secretary general Ban Ki-moon says that Snowden misused his rights to digital access and created problems greater than the public benefit of disclosure.
4 July Morales calls the rerouting of his flight an "open provocation" of "north American imperialism" and urges some European countries to "free themselves" from America.
4 July Ecuador distances itself from Snowden saying that he is under Russia's authority and would have to reach Ecuador before being granted asylum. Correa said the Ecuadorean consul acted without authority when it issued Snowden a temporary travel pass.
5 July The Washington Post, despite having published stories based on Snowden's leaks, now writes that he should be prevented "from leaking information that harms efforts to fight terrorism and conduct legitimate intelligence operations".
6 July Nicolás Maduro, the president of Venezuela, says he has decided "to offer humanitarian asylum" to Snowden. Nicaraguan president Daniel Ortega says he could accept Snowden's asylum request "if circumstances permit".
7 July Alexei Pushkov, chair of the Duma's foreign affairs committee, tweets that Venezuela's asylum offer may be Snowden's "last chance" to avoid extradition to the US.
8 July The Guardian releases the second part of its original video interview with Snowden. In this extract Snowden says he believes the US government "are going to say I have committed grave crimes, I have violated the Espionage Act. They are going to say I have aided our enemies".
10 July Glenn Greenwald, the Guardian columnist who has written many of the stories based on Snowden's information, says that Snowden maintains he didn't give classified information to China or Russia, following erroneous claims from the New York Times on 24 June that China had been "draining the contents of his laptop".
July 20 Destruction of Guardian computer equipment after threat of legal action by the UK government.
12 July Snowden sends a letter to human rights groups asking them to meet him at Sheremetyevo airport and claiming there is "an unlawful campaign by officials in the US government to deny my right to seek and enjoy... asylum". At the meeting he says he will be applying for temporary asylum in Russia while he applies for permanent asylum in a Latin American country.
24 July Anatoly Kucherena, a lawyer advising Snowden, states that the NSA leaker's asylum status has not been resolved and he will stay at Moscow airport for now. Kucherena claims that Snowden "intends to stay in Russia, study Russian culture", implying perhaps that Snowden may live in Russia for good.
August 1 Guardian publishes the story of secret American funding of GCHQ.
August 18 David Miranda, the partner of Guardian reporter Glenn Greenwald, held at Heathrow airport.
August 21 Guardian reveals how and why its computer equipment was destroyed.
