India and China, on Monday evening engaged in their first deadly conflict in at least 45 years, resulting in 20 deaths on the Indian side, including that of a commanding officer, and possibly 43 casualties including injuries on the Chinese side, pushing the bilateral relationship between the two nuclear powers to an all-time low.

Timeline of the weeks-long stand-off and the ensuing clash between India and China:

May 5-6: Violent clash between Indian and Chinese patrols on the northern bank of Ladakh’s Pangong Tso lake. Soldiers exchange blows, throw stones at each other and Chinese troops attack Indian soldiers with nail-studded clubs. Scores of soldiers (from both sides) injured in the skirmish involving 250 men.

May 9: Tensions spread to eastern sector. Heated confrontation between Indian and Chinese soldiers in north Sikkim’s Naku La area. Four Indian and seven Chinese soldiers injured during the face-off involving 150 soldiers.

May 10: Army issues statement confirming Naku La face-off, says aggressive behaviour by soldiers led to injuries on both sides. Army officers also confirm the Pangong Tso clash.

May 12: Reports of tensions building up in Galwan Valley emerge. In a statement, army reiterates “face-offs and aggressive behaviour occur” along the Line of Actual Control (LAC) with China as the boundary is not resolved.

May 19: As tensions simmer in Pangong Tso, Galwan Valley and Hot Springs, China’s foreign ministry accuses Indian troops of trespassing across LAC, saying Beijing had to take “necessary countermeasures” after the Indian side allegedly obstructed normal patrols by Chinese troops.

May 21: India strongly refutes China’s contention that tensions in the Ladakh and Sikkim sectors were triggered by Indian troops. External affairs ministry says Indian activities entirely on the Indian side of LAC and China hindering India’s normal patrols.

May 22: Army chief General Manoj Mukund Naravane makes a low-key visit to Leh-based 14 Corps headquarters for a security review of the sensitive sector. Troop build-up and military reinforcement from both sides.

May 25: China marshals close to 5,000 soldiers on its side of the disputed border in the Ladakh sector where India has also sent military reinforcements.

May 27: The army’s top brass discusses security issues including the ongoing border row with China in eastern Ladakh where Indian and Chinese soldiers are locked in a standoff at multiple points.

May 30: Defence minister Rajnath Singh says India and China talking to each other at military and diplomatic levels to resolve the standoff, assures the country that government will not allow India’s dignity to be hurt.

June 2: In the first official acknowledgement of a troop build-up along the border with China, Singh says a significant number of Chinese troops are present along LAC and that the Indian Army is matching the neighbour’s military moves.

June 6: In a rare meeting between top military officers, Lieutenant General Harinder Singh, commander of Leh-based 14 Corps, and Major General Liu Lin, commander of the People’s Liberation Army in South Xinjiang region, discuss de-escalation plan.

June 9: Army officers say China has begun withdrawing its soldiers from three hotspots along LAC, with India reciprocating by pulling back its forces deployed in those pockets. They say “limited military disengagement” has started in the Galwan valley, Patrolling Point 15 and Hot Springs.

June 10: Indian and Chinese delegations, led by Major General-rank officers, meet at Patrolling Point 14 at the Galwan Valley area as part continuing efforts to resolve the confrontation that has eased slightly with limited disengagement of forces at some LAC hotspots. This is the fourth round of talks between the two-star generals to break the stalemate.

June 12: Major General-rank officers meet for the fifth time to discuss de-escalation plan and ease border tensions. Chinese deployment in their ‘depth areas’ across LAC includes more than 8,000 troops, tanks, artillery guns, fighter bombers, rocket forces and air defence radars.

June 13: Army chief says disengagement of Indian and Chinese forces taking place in a “phased manner” along LAC with China where the situation is “under control”.

June 15: Army delegations from India and China hold discussions again. Talks take place at two locations along the LAC — brigadier-ranked officers meet in the Galwan Valley and Colonel-ranked officers in Hot Springs.The engagement between the two sides happens the same evening.