KIEV (Reuters) - A comedian with no political experience is tipped to win the first round of Ukraine’s presidential election on Sunday amid discontent over corruption and five years of war against pro-Russian separatists in the east of the country.

FILE PHOTO - Volodymyr Zelenskiy, Ukrainian comedian and candidate in the upcoming presidential election, hosts a comedy show at a concert hall in Brovary, Ukraine March 29, 2019. REUTERS/Valentyn Ogirenko

Here is a timeline of the main events in Ukraine’s political history since the country’s independence in 1991.

** 1991: Leonid Kravchuk, leader of the Soviet republic of Ukraine, declares Kiev’s independence from Moscow. In a referendum and presidential election Ukrainians approve independence by 92 percent and elect Kravchuk president.

** 1994: Kravchuk loses presidential election to Leonid Kuchma in elections deemed largely free and fair by observers.

** 1999: Kuchma is re-elected in 1999 in a vote riddled with irregularities. Appoints a new prime minister: Viktor Yushchenko, former chairman of the national bank.

** 2000: Journalist Georgiy Gongadze is murdered in what becomes one of post-Soviet Ukraine’s most notorious crime cases. The incident epitomizes the sleaze and violence of the Kuchma era and leads to street clashes.

** 2001: Kuchma fires his deputy prime minister for energy, Yulia Tymoshenko. Known as the ‘gas princess’ for her designer clothes and involvement in the gas industry, she is fired after charges of forgery and gas smuggling in her previous business are brought against her. Tymoshenko spends a month in detention. She denies the charges as a political witchhunt and is later cleared by the courts.

** 2004: Prime Minister Viktor Yanukovich, the pro-Moscow establishment candidate, takes on pro-European opposition leader Viktor Yushchenko in a presidential election. After a toxic race - during which Yushchenko’s face is disfigured in a poisoning attempt - Yanukovich is declared winner. But claims of vote-rigging trigger mass street protests known as the Orange Revolution, forcing a re-run of the vote. In a stunning reversal, Yushchenko is declared the new winner.

** 2005: Yushchenko comes to power in January, launching a pro-Western agenda that promises to modernize Ukraine and lead it out of the Kremlin’s sphere of influence, toward NATO and the European Union. He appoints Tymoshenko his prime minister, after her fiery speeches supporting the Orange Revolution gain her a dedicated following. But she soon falls out with the president and is sacked after less than eight months in office after much infighting.

** 2006: Following a row with Moscow over gas supplies, a parliamentary election produces a majority for Yanukovich’s pro-Moscow party. President Yushchenko accepts his rival as prime minister. Yanukovich gradually secures control over the economy and key government jobs.

** 2007: Parliamentary elections are held again, pro-“Orange” parties secure a tiny majority. In December, parliament votes in Tymoshenko as prime minister for a second stint.

** 2009: Amid another gas pricing row with Moscow, Tymoshenko starts negotiations with Russian Prime Minister Vladimir Putin to resolve a crisis that threatens to leave Europe without energy supplies.

** 2010: A fresh presidential election brings Yanukovich back to power, defeating Tymoshenko for the top job. His comeback is based on financial support from wealthy industrialists in eastern Ukraine, as well as promises to fight poverty. Russia and Ukraine clinch a new gas pricing deal, in exchange for an extension of a lease for the Russian navy in a Ukrainian Black Sea port.

** 2011: Tymoshenko is sentenced to seven years in prison over her 2009 gas deal with Russia on charges of abuse of power. She denies any wrongdoing and accuses Yanukovich of pursuing a political vendetta against her and her supporters.

** 2013: Yanukovich’s government suddenly announces suspension of trade and association talks with the EU in November and opts to revive economic ties with Moscow, triggering months of mass rallies in Kiev. Protests reach 800,000 by end-2013.

** 2014: Protests, largely focused around Kiev’s Maidan square, turn increasingly violent. Dozens of protesters are killed. In February, Ukraine’s parliament votes to remove Yanukovich, who flees. Tymoshenko is released from jail. Within days, armed men seize parliament in the Ukrainian region of Crimea and raise the Russian flag. Moscow annexes the territory after a referendum which shows overwhelming support in Crimea for joining the Russian Federation. In April, pro-Russian separatists declare independence and fighting breaks out in eastern Ukraine. In May, businessman Petro Poroshenko wins a presidential election with a pro-Western agenda. In July, a missile brings down the MH17 passenger plane, with the weapon used traced back by investigators to Russia, something Russia denies.

** 2017: An association agreement between Ukraine and the European Union is passed, opening both markets for the free trade of goods and services, as well as visa-free travel to the EU for Ukrainians.

** 2018: A naval clash between Russian border guards and Ukrainian ships in the Kerch Strait near Crimea leads Poroshenko to declare martial law.

** 2019: The Ukrainian Church secures autonomy from the Russian Orthodox Church, angering the Kremlin.

The first round of voting in Ukraine’s presidential election will take place on Sunday. If no candidate secures a majority, the election will move to a second-round run-off on April 21.