The Battle of Chawinda was a major engagement between Pakistan and India during the Indo-Pakistani war of 1965 as part of the Sialkot campaign. It is well known as being one of the largest tank battles in history since the Battle of Kursk, which was fought between the Soviet Union and Nazi Germany in World War II.
The initial clashes in Chawinda coincided with the Battle of Phillora, and the fighting here intensified once the Pakistani forces at Phillora retreated. The battle came to an end shortly before the United Nations Security Council mandated an immediate ceasefire, which would formally end the hostilities of the 1965 war.
The Sialkot campaign was part of the strategy of riposte that India had devised to counter Pakistan's advances into Jammu and Kashmir (J&K). It called for relieving Jammu by advancing from either Samba (in J&K) or Dera Baba Nanak (in Indian Punjab) with a view to encircling the city of Sialkot along the Marala–Ravi Link Canal (MRL).
The canal starts from the Marala Headworks on the Chenab River close to Pakistan's border with J&K, and runs to the west and south of Sialkot, eventually draining into the Ravi River near the town of Narang Mandi.
The GOC Western Command Gen. Harbakhsh Singh favoured launching the campaign from Dera Baba Nanak using the 1st Armoured Division. But he was overridden by the Chief of Army Staff Gen. J. N. Chaudhuri, who created a new I Corps under the command of Lt. Gen. Pat Dunn for the purpose. It would operate from Samba.
Gen. Dunn was given an assortment of units. In addition to the 1st Armoured Division under Maj. Gen. Rajinder Singh, he had:
the 6th Mountain Division under Maj. Gen. S. K. Korla
the 14th Infantry Division under Maj. Gen. Ranjeet Singh and
the 26th Infantry Division under Maj. Gen. M. L. Thapan.
The new corps was still in the process of formation when the hostilities broke out in September 1965. Some of the units were also under-strength because of their forces being tied up elsewhere. According to the Indian official history, the force contained 11 infantry brigades and 6 tank regiments.
The Pakistani forces opposing the Indian thrust were part of Pakistan's I Corps under Lt. Gen. Bakhtiar Rana. Included in it were:
the 6th Armoured Division commanded by Maj. Gen. Abrar Hussain,
the 4th Artillery Corps under Brig. Amjad Ali Khan Chaudhury (affiliated to the 6th Armoured Division), and
the 15th Infantry Division under Brig. S. M. Ismail.
The 15th Infantry Division was a mixed infantry and armour force, with four pairs of a brigade and an armoured regiment each. However, only one out of the four pairs (the 24th Brigade and 25th Cavalry) was in the conflict area when the Indian campaign started. They were based in and around Chawinda. The 24th Brigade was commanded by Brig. Abdul Ali Malik and the 25th Cavalry was led by Lt. Col. Nisar Ahmed Khan.
The 6th Armoured Division, normally based at Gujranwala, was moved to Pasrur in preparation for the war. It had three cavalry regiments: 10th Cavalry (also called the Guides Cavalry), the 22nd Cavalry and the 11th Cavalry. The 11th Cavalry, along with the 4th Artillery Corps, was in Chamb as part of Operation Grand Slam when the operations started. The units were recalled and deployed in the vicinity of Phillora by 8 September.
Later reinforcements included the 8th Infantry Division and 1st Armoured Division.
The main striking force of the Indian I Corps was the 1st Armoured Division, which was supported by the 14th Infantry and 6th Mountain divisions. Indian forces seized the border area on 7 September 1965. This was followed by a short engagement at Jassoran in which the Pakistanis suffered losses in the form of about 10 tanks, consequently ensuring complete Indian dominance over the Sialkot-Pasrur railway.