Muslim Invasions of Assam were military invasions conducted by Turko-Afghans, Bengal Sultanate, and Mughal Empire to assert political control over Assam that began in 1206,"The year 1205-6 is a significant landmark in the annals of Assam, earlier Kamarupa. It marked the beginning of the repeated invasions of Kamata and Kamrup by the Turko-Afghan rulers of Bengal and followed by the Mughals which continued with occasional breaks till the last quarter of the seventeenth century." when the Ghurid Muhammad Bakhtiyar Khalji invaded a fringe of Kamarupa with the last in 1671 when the Mughal commander Mirza Raja Ram Singh I tried unsuccessfully to take Assam at the Battle of Saraighat."He commissioned Ram Singh of Amber, son of the distinguished general Mirza Rajah Jai Singh, and a Commander of 4000, to lead an invasion of Assam." The Ahom kingdom removed the vestigial Muslim power from Western Assam up to the Manas river in 1682 after the Battle of Itakhuli."In the Battle of Itakhuli in September 1682, the Ahom forces chased the defeated Mughals nearly one hundred kilometers back to the Manas River. The Manas then became the Ahom-Mughal boundary until the British occupation."
Pre-Mughal invasions Early invasions (c. 1206-1228) Historians consider Muhammad Bakhtiyar Khalji's invasion of Tibet (1205–1206) that touched Kamarupa as the first invasion of Assam by a Muslim commander. His retreating army was annihilated by a king in Kamarupa;
In 1228 AD, Nasiruddin crossing through Jalpaiguri advanced into Kamrup. The king of Kamarupa erected fortifications for defence but faced a conspiracy of an assassination against him, and was killed by the son of Iltutmish, Nasiruddin Mahmud. Nasiruddin appointed a tributary king to the Kamarupa throne, but he died in 1229 and Bengal was plunged into political chaos till around 1251, Assam remained an unknown region to the Muslim rulers.
Yuzbak's invasion (1257)
Malik Ikhtiyaruddin Yuzbak, previously a governor of Lakhnauti (in present-day West Bengal) under the Delhi Sultanate and newly independent since 1255, invaded Kamarupa at the beginning of spring 1257 during a period of internal strife and power struggle in the Delhi Sultanate. The Kamarupa king's domain was between Karatoya in the west and Barnadi in the east, with the capital at Kamarupanagara in present-day North Guwahati. The Kamarupa king beat a strategic retreat to the hills, dammed the hill stream, and allowed his subjects to submit to the invader. When the spring rains started, he removed the dams, flooding the plains and then sallied out and cut off logistic lines to the capital using guerrilla tactics. Yuzbak tried to retreat, but he was soon surrounded by Kamarupi troops, caught, and executed;"Finally the Bengal army was routed in an open encounter in a narrow mountainous defile. An arrowshot wounded the elephant-borne Sultan in the chest. The Rajah allowed the captured Sultan to see his son before being killed. But his family members and dependants were imprisoned, and only a handful could escape to Bengal" though others have reported that Yuzbak died of his wounds.
This invasion is significant for a number of reasons: Yuzbak was the first to build a mosque in Assam and had the khutbah read;"Collecting huge spoils of victory and desirous of permanent occupation of such a rich and prosperous land, he constructed a mosque at the capital to spread Islam, and had the khutbah read." his pattern of defeat was to repeat a few hundred years later during Mir Jumla's invasion of Assam"[T]he Rajah sallied out of his hill refuge, and, following the local defensive guerrilla tactics, cut the water dykes open, flooding the land, submerging the spring harvest. As pre-arranged, the people threw off the Muslim yoke, reoccupied the plains and waterways, and blocked the transport of provisions to the capital. Death from starvation stared the invaders in the face. Their plight anticipated that under Mir Jumla four hundred years later"
Giyasuddin Bahadur Shah's campaign (c. 1321-22) In 1321–1322, Ghiyasuddin Bahadur Shah of Bengal embarked on a military campaign from Sonargaon, advancing along the old course of the Brahmaputra River toward the southeastern frontier of Kamrupa, encompassing Enayetpur and Ghiyaspur. From this base, he launched an attack on the interior, targeting the region corresponding to modern-day Koch Bihar. The resistance led by Pratapdhwaj (), a usurping minister of Kamata, proved ineffective against the Sultan's forces. Continuing his campaign, Ghiyasuddin Bahadur Shah proceeded along the Brahmaputra and conducted a rapid, plundering raid as far as Nagaon. However, the Kacharis, who controlled the region at the time, repelled his forces, inflicting significant losses. Consequently, Ghiyasuddin Bahadur Shah's invasion yielded no lasting territorial gains. In 1327–1328, he was defeated and killed by the forces of Sultan Muhammad Tughlaq of Delhi, who subsequently annexed Bengal.
Campaign of Shamsuddin Ilyas Shah (1356–57) In 1356–57 AD, Shamsuddin Ilyas Shah, who unified Bengal and established the Bengal Sultanate, carried out campaigns in Kamata-Kamrup towards the end of his reign. The rulers of Kamata lacked the resources and capability to effectively counter the invasion, their authority having been weakened by repeated attacks from the Ahom king Sukrangpha () in the east, pressure from the Kacharis south of the Brahmaputra, and the emergence of independent local chiefs in Kamrup, one of whom is recorded as having asserted independence by 1329. These conditions allowed Ilyas Shah to advance rapidly up the Brahmaputra through northern Mymensingh district and penetrate the core of Kamata-Kamrup between the Manas and Bornadi rivers. The Bengal forces made substantial progress in occupying Kamrup, including its capital Guwahati, before Ilyas Shah's death around November 1357.
Campaign of Sikandar Shah (c. 1357–62) Ilyas Shah's son and successor, Sikandar Shah (), continued the campaign in Kamrup. Numismatic evidence supports a temporary Bengal occupation of the region: Sikandar Shah struck silver coins bearing the mint names Chawlistan urf Kamrup or Arsah Kamru, identified by scholars such as Abdul Karim with the Kamrup mint. Since no other coin of his has so far been reported bearing the Kamrup mint, it is difficult to surmise whether he kept Kamrup under his control for a considerable time.
After several years, during Sikandar Shah's absence, local Bhuyan chiefs, together with the Kamata ruler and the Kachari ruler Mahamanikya, are said to have organised resistance against the Bengal army of occupation. Sikandar Shah subsequently advanced eastwards along the Brahmaputra, reaching the Kapili valley in present-day Nagaon district around 1362. This Yavana or Bangal invasion has been recorded in the Gachtal stone inscription found at Dabaka in the Kapili valley. The inscription indicates that the invading army had penetrated eastwards as far as the Davaka region and records that nearly three thousand enemy troops were trapped and driven downstream through the coordinated use of riverine warfare and seasonal floods. On this basis, it has been suggested that forces associated with the Kamata king, the local Bhuyans and the Kachari ruler Mahamanikya resisted Sikandar Shah's eastward advance at Gachtal near the Kapili River, checking the Bengal campaign in the region.
Ghiyasuddin Azam Shah's campaigns (1389–1399) Ghiyasuddin Azam Shah, the successor of Sikandar Shah, took advantage of continuing political instability in Kamata-Kamrup to extend the authority of the Bengal Sultanate into the region. The Kamata kingdom had already been weakened by repeated invasions from Bengal during the 13th and 14th centuries. Epigraphic evidence indicates that Ghiyasuddin had extended his authority into Kamrup by the closing decades of the 14th century. A Persian stone inscription discovered at Boko, Kamrup, dated to 1389 AD and issued during the reign of Ghiyasuddin Azam Shah, has been interpreted as evidence that his sovereignty extended through Guwahati as far west as Boko.Owahedur Zaman, "Study on the Persian Inscriptions discovered in Assam", p. 5: "This stone slab inscription is from the time of Ghiyasuddin Azam Shah (ruled from 1389 A.D. to 1410 A.D). It was discovered in Boko of Kamrup district which was issued by Sultan Ghiyasuddin Azam Shah in 1389 A.D. It seems that he extended his sovereignty through Guwahati upto Boko area." The inscription has also been cited as indicating that at least part of the Kamrup region remained under the Sultanate's control for some period during his reign. Further evidence is provided by a copper-plate inscription dated to 1399 AD (1321 Shaka), discovered in the Helem area of present-day Biswanath district. In describing the southern boundary of a land grant in the Nakuchi region of Hajo, the plate refers to land formerly enjoyed by officials such as gantri and mantri-pali "when Sri Ghiyasuddin ruled Kamrup", indicating that Ghiyasuddin's authority was remembered in connection with the administration of land in the region.Helem copper plate dated to 1399, p. 6 Another portion of the inscription refers to the defeat of the ruler of Gauda by a king whose name is said to be illegible or unclear, suggesting that Ghiyasuddin's control over the region was subsequently challenged.Helem copper plate dated to 1399, p. 6
Numismatic evidence further points to Ghiyasuddin's political and military presence in Kamata-Kamrup. Coins dated 799 AH (1396–97 CE) have been found in Koch Bihar, while coins dated 802 AH (1399–1400 CE) have been reported from Guwahati. These finds have been interpreted as evidence either of renewed campaigning or of continuing political influence by the Bengal Sultanate in the region. According to one reconstruction, the Kamata ruler, faced with this pressure, formed a matrimonial alliance with the Ahom ruler and subsequently succeeded in driving the Sultanate's forces back across the Karatoya River. The successive campaigns and counter-campaigns contributed to continuing political instability in western Assam during the late 14th century.
Ruknuddin Barbak Shah's campaign (c. 1460–74) During the reign of the Bengal Sultan Ruknuddin Barbak Shah (1459–1474), another conflict is reported between the Bengal Sultanate and the ruler of Kamata-Kamrup. The principal account of the campaign is the much later Persian work Risalat-us-Shuhada, which describes the local ruler as Kameswar or Kamateswar. J. N. Sarkar notes that the account was composed nearly two centuries after the events and contains legendary elements, while the campaign is not corroborated by contemporary Persian or Assamese chronicles, numismatic evidence or inscriptions.
According to this tradition, Barbak Shah had suffered several unsuccessful expeditions against Kameswar before appointing Shah Ismail Ghazi to lead a renewed campaign, probably around 1460. The operations were centred in the eastern part of the Dinajpur region, where the Bengal forces sought to recover territory west of the Karatoya River that had been occupied by forces from Kamata-Kamrup. Kameswar offered strong resistance and defeated Ismail's forces near Santosh, after which negotiations followed. The Risalat-us-Shuhada claims that Kameswar eventually acknowledged the authority of the Bengal Sultan, although the historicity and precise outcome of the episode remain uncertain.
Ismail Ghazi was subsequently accused by the Bengal frontier official Bhandsi Rai of having entered into an alliance with Kameswar with the intention of establishing an independent principality. Barbak Shah ultimately ordered Ismail's execution in January 1474.
Shamsuddin Muzaffar Shah's campaign (c. 1492)