LONDON (Reuters) - Royal Dutch Shell pioneered Nigeria’s oil and gas industry and remains a major investor in the West African country. But over the decades it has come under fire over spills in the Delta region and struggles with oil theft, corruption and oil-fueled violence.

A view shows the Bonny oil terminal in the Niger delta which is operated by Royal Dutch Shell in Port Harcourt, Nigeria August 1, 2018. Picture taken August 1, 2018. To match Insight NIGERIA-SECURITY REUTERS/Ron Bousso

Following are some of the highlights of Shell’s history in Nigeria:

1936 - The Royal Dutch Shell Group establishes a Nigerian venture with the precursor company of BP Plc. The first shipment of oil from Nigeria takes place in 1958.

April 1973 - Nigerian government takes a stake in the venture. Over the coming years, the government increases its stake and BP exits.

1979 - The Shell Petroleum Development Company of Nigeria (SPDC) is established, incorporating assets of the older Shell-BP consortium. Over time, the Nigerian National Petroleum Corporation comes to own 55 percent, Shell owns 30 percent, France’s Total owns 10 percent and Italy’s Eni 5 percent. Shell remains the operator.

1990 - The Movement for the Survival of the Ogoni People (MOSOP), led by firebrand environmental rights activist Ken Saro-Wiwa, starts campaigning for a fairer share of oil wealth for the Ogoni people living on oil fields and compensation for environmental damage.

January 1993 - MOSOP organises protests of around 300,000 Ogoni people against Shell and oil pollution. Nigeria’s military government occupies the region.

April 1993 - Shell forms Shell Nigeria Exploration and Production Company Limited (SNEPCo), which signs Production Sharing Contracts to develop offshore oil and gas interests.

1993 - Shell ceases production in Ogoniland.

November 1995 - Saro-Wiwa and eight other MOSOP leaders are executed by Sani Abacha’s military government on alleged murder charges, to worldwide horror. Nigeria is suspended from the Commonwealth.

Late 1990s - Over time, Shell’s focus shifts to offshore exploration, where it enjoys better margins and fewer threats of attack by militants.

October 2003 - SPDC pumps more than 1 million barrels of oil per day.

2005 - Shell starts production at the giant Bonga offshore field.

2006 - Militant group MEND (Movement for the Emancipation of the Niger Delta) emerges and begins to attack Shell facilities. Like MOSOP it seeks a great share of oil wealth for the Delta’s people and remediation for oil spills. SPDC pump stations and platforms in Niger delta are attacked and production falls.

2008 - Two large spills, a result of operational faults, hit the community of Bodo in Ogoniland in the Niger Delta. Tens of thousands of barrels of oil are spilt.

January 2010 - SPDC sells some onshore fields and says it is no longer looking to Nigeria for growth.

April 2011 - Shell and Italy’s Eni acquire oil production licence (OPL) 245, a large offshore field, for $1.1 billion from local company Malabu.

August 2011 - A U.N. report criticises Shell and the Nigerian government for contributing to 50 years of pollution in Ogoniland which it says needs the world’s largest oil clean-up, costing an initial $1 billion and taking up to 30 years.

March 2012 - A group of 11,000 Nigerians from Bodo, Ogoniland, launch a suit against Shell at the London High Court, seeking tens of millions of dollars in compensation for the 2008 oil spills.

January 2013 - A Dutch court rules that Shell could be held partially responsible for pollution in the Niger Delta, saying the company should have prevented sabotage at one of its facilities. Four Nigerians and Friends of the Earth filed the suit originally in 2008 in the Netherlands.

January 2015 - Shell accepts liability for the Bodo spills, agreeing to pay 55 million pounds ($83 million at the time) to Bodo villagers and to clean up their lands and waterways.

May 2018 - Court case against Shell and Eni over the 2011 OPL 245 acquisition starts in Milan. Nine current and former executives and contractors, including ENI Chief Executive Claudio Descalzi, are accused by Italian prosecutors of paying bribes to secure the license.