Reuters Edge

TIMELINE: Sri Lanka -- 25 years of civil war

(Reuters) - Sri Lanka’s advance into the rebel Tamil Tigers’ heartland has unleashed the bloodiest combat in a decade and opened a new phase of the 25-year-old conflict.

Tamil Tiger rebels are fighting for an independent state in the north and east of the island and tens of thousands of people have died in the war and many more displaced.

Here are some milestones charting the conflict, whose end seems elusive after the collapse of a barely observed 2002 ceasefire in January.

1948 - Island of Ceylon gains independence from Britain.

1956 - Government makes majority Sinhala language the language of state. Minority Tamils say they feel marginalized.

1958 - First anti-Tamil riots break out, killing dozens and forcing thousands from their homes. Becomes a watershed event in mutual distrust between Sinahalas and Tamils.

1972 - Country renamed Sri Lanka, becomes republic. Buddhism designated the principal religion.

1976 - Liberation Tigers of Tamil Eelam (LTTE) formed by militant Velupillai Prabhakaran.

1983 - Tiger attack in north kills 13 soldiers, triggering vast anti-Tamil riots in capital, Colombo. Hundreds die, thousands flee. Start of what Tigers call “First Eelam War”.

1987 - Having earlier armed Tigers, India sends troops to enforce truce. Tigers renege on pact, refuse to disarm and begin three years of fighting that kills 1,000 Indian soldiers.

1990 - India withdraws. LTTE controls northern city of Jaffna; Tigers overrun police stations in east. “Second Eelam War” begins.

1991 - Suspected Tiger suicide bomber kills former Indian prime minister Rajiv Gandhi in south India.

1993 - President Ranasinghe Premadasa assassinated by suicide bomber. LTTE widely blamed.

1995 - President Chandrika Kumaratunga agrees truce with rebels. “Eelam War 3” begins when rebels sink naval craft. Tigers lose Jaffna to government forces.

1995-2001 - War rages across north and east. Suicide attack on Central Bank in Colombo kills around 100. Kumaratunga wounded in another attack.

2001 - Tiger attack on main international airport destroys half of Sri Lankan Airlines fleet. Economic growth ceases.

2002 - Landmark ceasefire signed after Norwegian mediation.

2003 - Tigers pull out of peace talks, ceasefire holds.

2004 - Tiger offensive regains control of east. Asian tsunami hits in December, killing around 30,000 Sri Lankans.

2005 - Suspected Tiger assassin kills foreign minister. Rebel election boycott helps perceived anti-Tiger hardliner Mahinda Rajapaksa win presidency. Attacks on military rise.

2006 - Both sides renew commitment to 2002 truce in Geneva in February; but as fighting flares April-July many fear start of “Eelam War 4”. New Geneva talks fail in October; artillery battles follow in Jaffna.

2007 - Government captures Tiger’s eastern stronghold of Vakarai in January; tens of thousands displaced. In July, government says it has driven rebels from their last jungle stronghold in east. In October, suicide fighters mount their biggest ground assault since civil war began on a north-central airbase.

2008 - Government annuls 2002 ceasefire in early January. First eight days of year sees main opposition parliamentarian T. Maheshweran shot dead in Colombo, and Nation Building Minister D.M. Dassanayake killed by a roadside bomb blamed on Tigers. Military advances toward Tiger strongholds in north on four fronts, bringing war to doorstep of rebel-held turf by August. As of late August, military says it is within artillery distance of LTTE’s main administrative city, Kilinochchi.

Writing by Nagesh Narayana and Rob Dawson; Editing by Gillian Murdoch