As part of a sweeping restructuring of the oil industry, Yukos is created by a merger of two state companies - Siberian oil producer Yuganskneftegaz and Volga refining company Kuibyshevnefteorgsintez.
End-1995
Still in state hands, Yukos is on the brink of bankruptcy amid falling output and rising debt; it owes the government alone $3.5 billion.
1995-96
Through a series of share offers, Yukos becomes the first fully privatized integrated oil company in Russia. Mikhail Khodorkovsky, a billionaire who made his fortune in banking, acquires the company for a sum estimated to be between $200 million and $1.5 billion.
1998
Khodorkovsky starts a major restructuring and modernization program, with the aim of making Yukos an oil giant on a par with international peers, including putting in place accepted standards for corporate conduct and financial stability. The idea is first mooted of merging with Sibneft, another large producer then controlled by billionaire Boris Berezovsky.
Bank Menatep, Yukos' investment vehicle, defaults on loans and cash flows are believed to been diverted offshore - much to the anger of minority shareholders.
1999
The company is fined by regulators after neglecting to file its quarterly results.
2000
Yukos launches a corporate governance charter, and publishes its accounts to international standards.
At the same time, newly-elected President Vladimir Putin strikes a deal with 20 of the "oligarchs" of the 1990s, including Khodorkovsky. It is believed Putin and the "oligarchs" struck the following deal: The "oligarchs" can tend to their business interests as long as they stay away from politics.
2001
Yukos shares are listed in New York, London, Frankfurt, Berlin and Munich. The company becomes a major supplier to China after the acquisition of a refinery and other assets in the Russian Far East.
2002
Yukos acquires Lithuania's main oil company, a move into Slovakia, and plans to develop a pipeline to China.
2003
Khodorkovsky publicly disagrees with the Kremlin over state control of the pipeline industry. He complains publicly about corruption, and begins openly funding various opposition parties, including the Communists.
On July 2, Platon Lebedev, a major Yukos shareholder, is arrested and accused of having illegally acquired shares in Apatit, a fertilizer company, in 1994. Khodorkovsky is questioned and released two days later.
16 July, 2003
Russian tax authorities declare their intention to audit Yukos' books, as the investigation into the Apatit deal is dramatically widened. Yukos's offices are raided and records seized.
25 October, 2003
Khodorkovsky is arrested during a visit to Siberia, flown to Moscow and charged with various counts of fraud and tax evasion.
30 October, 2003
The authorities arrest the 44% stake in Yukos owned by Bank Menatep. Previously, Yukos had announced a $2 billion dividend to shareholders - an attempt to extract money from the firm ahead of any possible re-nationalization.
3 November, 2003
Khodorkovsky resigns as chief executive of Yukos in favor of American citizen Simon Kukes, and is reported to have handed his interest in the company over to associates outside Russia. Kukes tries to distance Yukos from Khodorkovsky, underplaying previous plans to sell the company to a foreign investor.
30 December, 2003
Yukos is hit with a back tax bill for $3.5 billion for under payment of tax 2000 obligations.
11 March, 2004
More than $5 billion belonging to Yukos shareholders is arrested in Switzerland, after the authorities claim the money has been stolen. Arrest warrants are issued for another 10 of the company's senior associates.
27 May, 2004
Yukos warns it will have to file for bankruptcy if the $3.5 billion tax demand stands.
16 June, 2004
Khodorkovsky's trial begins, with the threat of up to 10 years in prison. The court decides on an immediate adjournment.
6 July, 2004
Yukos is served with another demand for $3.4 billion in unpaid taxes from 2001.
12 July, 2004
The trial resumes. Prosecutors argue that Khodorkovsky and Lebedev ran an "organized criminal group". Khodorkovsky says the charges are "absurd".
20 July, 2004
Russian bailiffs say they will sell off Yuganskneftegaz, Yukos' main production unit, to pay off its tax arrears.
2 August, 2004
Tax inspectors begin looking at Yukos' 2002 accounts, settling the stage for a third multi-billion-dollar demand.
1 November, 2004
Yukos is served with another $10 billion tax bill related to 2002 operations. Uncertainty remains over the future of Yuganskneftegaz. Yukos says its production will imminently come to a halt unless the situation surrounding any sale can be resolved.
25 November, 2004
All Yukos' top executives are reported to have left Russia, apparently fearing arrest.
Three firms, including dominant gas producer Gazprom, submit bids for the 19 December auction of Yuganskneftegaz.
15 December, 2004
Yukos files for bankruptcy in the U.S., in an attempt to halt the sale of Yuganskneftegaz.
16 December, 2004
A U.S. bankruptcy judge issues a temporary injunction halting the Yuganskneftegaz sale. But Russian officials say the Houston court has no jurisdiction in the case and call the ploy "nonsense."
19 December, 2004
Auction of Yuganskneftegaz in Moscow, which is sold to little-known firm Baikalfinansgroup for $9.35 billion.
23 December, 2004
State-owned oil firm Rosneft - itself preparing for a merger with state-controlled gas giant Gazprom - buys Baikal, thus acquiring Yuganskneftegaz.
12 January, 2005
Mikhail Khodorkovsky hands over controlling stake in Yukos parent firm Menatep to fellow shareholder Leonid Nevzlin, now living in Israel and wanted in Russia on murder charges.
9 February, 2005
Menatep says it plans to sue Russian government for $28 billion.
14 February, 2005
Yukos sues Rosneft, Baikal, and Gazprom and one of its units, claiming damages of $20 billion for their alleged role in the Yuganskneftegaz auction.
25 February, 2005
A U.S. court dismisses Yukos' bankruptcy petition.
15 March, 2005
Rosneft sues Yukos over an $11bn back tax bill allegedly owed by Yuganskneftegaz.
25 March, 2005
Ex-Yukos security chief Alexei Pichugin is convicted of murder and attempted murder.
19 April, 2005
Russian court freezes more Yukos assets as its own former unit Yuganskneftegaz accuses it of having paid below-market prices for its oil and demands $6 billion in compensation.
27 April, 2005
Judges postpone their verdict on Mikhail Khodorkovsky until 16 May.
31 May, 2005
After 12 days of summing up the trial, the judges find Khodorkovsky and Lebedev guilty of six charges including tax evasion and sentence them to nine years in prison each.
22 September, 2005
Khodorkovsky and Lebedev lose an appeal against convictions for fraud and tax evasion dismissed by a court in Moscow. The court upheld all but one count against Khodorkovsky, cutting his jail sentence from nine to eight years.
24 November, 2005
Yukos win a small victory when a Dutch court ruled that Russian state-owned Yuganskneftegaz could only seize shares that Yukos' Dutch subsidiary Yukos Finance holds in Dutch affiliates.
28 November, 2005
The Moscow Lefortovo Court finds Alexei Kurtsin, the property manager of the Moscow branch of embattled oil company Yukos, guilty of embezzlement and laundering money. The same court found Yukos-Moscow Senior Vice President Mikhail Trushin guilty of laundering money.
