India and Pakistan have had testy relations at best since independence. Some key dates that helped define the South Asian nations:

August 1947 – Britain ends its colonial rule over the Indian subcontinent, which becomes two independent nations – Hindu-majority, but secularly governed India and the Islamic republic of Pakistan. The division, widely known as Partition, sparks massive rioting that kills up to 1 million, while another 15 million flee their homes in one of the world s largest human migrations.

October 1947 – The two young nations begin a war over control of Kashmir, a Muslim-majority kingdom ruled by a Hindu maharaja. A U.N.-brokered cease-fire ends the war in a year with Kashmir divided between them.

January 1949 – India and Pakistan agree to a U.N. Security Council resolution calling for a referendum in which Kashmiris would determine their future; the vote never takes place.

September 1960 – India and Pakistan sign a World Bank-brokered Indus Water Treaty governing three rivers. It is the only India-Pakistan treaty that has held.

August 1965 – A second war begins over Kashmir, ending a month later in another U.N.-mandated ceasefire.

December 1971 – A third war is fought, this time as India supports secessionists in East Pakistan. The war ends with the creation of Bangladesh.

July 1972 – The countries  prime ministers sign an accord for the return of tens of thousands of Pakistani prisoners of war.

May 1974 – India conducts a nuclear test, becoming the first nation to do so that s not a permanent U.N. Security Council member.

December 1989 – Armed resistance to Indian rule in Kashmir begins. India accuses Pakistan of giving weapons and training to the fighters. Pakistan says it offers only “moral and diplomatic” support.

May 1998 – India detonates five nuclear devices in tests. Pakistan detonates six. Both are slapped with international sanctions.

February 1999 – Indian Prime Minister Atal Bihari Vajpayee rides a bus to the Pakistani city of Lahore to meet with Pakistan counterpart, Nawaz Sharif, and sign a major peace accord.

May 1999 – Conflict erupts in Kargil as Pakistani forces and Kashmiri fighters occupy Himalayan peaks. India launches air and ground strikes. The U.S. brokers peace.

May 2001 – Vajpayee and Pakistan s President Pervez Musharraf meet in the Indian city of Agra, but reach no agreements.

October 2001 – Insurgents attack the legislature building in Indian-controlled Kashmir, killing 38 people.

December 2001 – Gunmen attack India s Parliament, killing 14. India blames militant groups Lashkar-e-Taiba and Jaish-e-Muhammad, and deploys troops to its western frontier with Pakistan. The standoff ends in October 2002 after international mediation.

January 2004 – Musharraf and Vajpayee hold talks, launching bilateral negotiations to settle outstanding issues.

February 2007 – A train service between India and Pakistan, the Samjhauta Express, is bombed in northern India, killing 68.

October 2008 – India and Pakistan open a trade route across divided Kashmir for the first time in six decades.

November 2008 – Gunmen attack Mumbai, killing 166 people. India blames a Pakistan-based militant group.

May 2014 – India s new Prime Minister Narendra Modi invites Pakistani counterpart Nawaz Sharif to New Delhi for his inauguration.

December 2015 – Modi makes a surprise visit to the Pakistani city of Lahore on Sharif s birthday and the wedding of his granddaughter.

January 2016 – Six gunmen attack an Indian air force base in the northern town of Pathankot, killing seven soldiers in a battle that lasted nearly four days.

July 2016 – Indian soldiers kill Kashmiri rebel leader Burhan Wani, sparking months of anti-India protests and deadly clashes in the region.

September 2016 – Suspected rebels sneak into an Indian army base in Kashmir and kill 18 soldiers. Four attackers are also killed.