Brief mention must be made of the political cataclysm of Sind, which was the centre of the Ismaili mission down to the 18th century. After the end of the Sumra rule in Sind around 762/1361, the field was open for the Sammahs, who took possession of Sind and raised their chief, called Unar to the throne with the title of Jam. He died most probably in 768/1367 and was succeeded by his nephew, Jam Tamachi. He was followed by Jam Khairuddin, then Jam Babinah. Soon afterwards, Firuz Khan Tughlaq (1320-1388) invaded Sind after subjugation of Gujrat and some other parts of India. He defeated Jam Babinah, thus Sind fell into the hands of Firuz Khan. The Sammah rule ended in Sind in 926/1519, when Shah Beg Arghun (d. 928/1521) defeated Jam Firuz, the last ruler of the Sammah in 926/1519 and established Arghun dynasty in Sind.
The Arghun dynasty lasted till 961/1554, when their second ruler passed away during the war of succession. It was followed by a new dynasty of Central Asian origin; they were the Trakhans, whose monuments are still visible in Makli Hill. A certain Mirza Essa Trakhan (d. 974/1566) being the first ruler, took the reign in 961/1554. In 1000/1592, the Mughal emperor Akbar's friend, Abdur Rahim defeated Mirza Jani Beg Trakhan and annexed Sind to the Mughal empire. The trade from Afghanistan and Central Asia to the subcontinent was mainly in the hands of Hindu merchants in Shikarpur. This town was founded by Daudpotra in 1025/1616, a family who had assumed power in a large area of upper Sind. The Daudpotras were then defeated by another clan, the Kalhora. The first man to be known from this family was Adam Kalhora, who was executed in Multan in 965/1558. In the meantime, the British East India Company began to establish trade with Sind between 1045/1636 and 1073/1662. In 1112/1701, Yar Muhammad Khan Kalhora seized Shikarpur and the Mughal emperor Aurengzeb also granted the family large areas in Sind. He was succeeded by Nur Muhammad in 1131/1719, whose territory extended from Multan to Thatta. In the interim, the invasion of Nadir Shah in 1152/1739 proved as severe blow to the Kalhoras as it was to the Mughals. Nur Muhammad had to give up Shikarpur and Sibi and the Afsharids of Iran kept the whole western bank of the Indus. About fifteen years later, Ahmad Shah Durrani invaded Sind in 1167/1754, but, although Nur Muhammad was driven out from Jaisalmer, his son Muhammad Murad Yar Khan gained the kingdom. His brother Ghulam Shah founded Hyderabad in place of the old Nerankot in 1181/1768. The Kalhora period was important for the development of Sindhi literature, though its economic condition rapidly deteriorated towards the last quarter of the 18th century. The minister of the last Kalhora prince, Mir Bijar was killed in 1196/1781 after having defeated the invading Afghans near Shikarpur. Mir Bijar belonged to the Baluch clan of the Talpurs who were the disciples of the Kalhora, but after his death, fight between the two groups ensued and in 1197/1783, the Talpur Mir Fateh Ali defeated the last Kalhora, Abdun Nabi. The rule of the Talpur Mirs was divided among the branches of the family, therefore, the Talpurs were seated in Hyderabad, Mirpur and Khairpur. The Talpurs were plain blunt shepherds, who mostly relied on the power of their Baluchi clans to maintain order. The battle of Miami in 1259/1843 with the British India finally got an end of the rule of the Talpur Mirs in Sind.
Returning the thread of our narrative, the scrutiny of traditions suggests that Pir Sadruddin started his proselytizing mission between 757/1356 and 798/1396 under Pir Shams. Judging from bits and shreds of the accessible traditions, it is known that he selected twelve gifted surrogates from different tribes to assist him in his mission. He seems to have travelled from Uchh to the lower part of Sind as far as the regions adjoining the Indian ocean, and around the locality of present Karachi. The tradition has it that he hired a camel in that locality to travel into the interior Sind, and converted the owner of camel at first. Pir Sadruddin seems to have launched his brisk mission in the district Thatta, and converted a bulk of the Lohana and Bhatia castes. From lower Sind, he proceeded to the middle, and also visited Kutchh with a group of dais. His mission also penetrated in Gujrat and the regions between northern India and Deccan. He also tried to bring the lower castes into the Ismaili fold, who revered Ramdeo, wherein he cloaked his identity, assuming the name of Nizar - a familiar term among the followers of Ramdeo. It must be known that he composed few ginans bearing the name Nizar for the followers of Ramdeo. His mission also influenced other parts of Gujrat and Kathiawar.
Pir Sadruddin visited Iran in 798/1396 to report Imam Islam Shah the outcome of his endeavours. He was designated as the hujjat of Sind and Hind, or the pir according to the Indian tradition. With fresh directions, he returned to India and established prayer-halls (khana) and appointed mukhi (derived from mukhia means "foremost"), the headman at Sind. Each community was administered by its headman (mukhi), who was an executive head and his office was no longer hereditary as he was periodically selected. His powers and duties were explicitly defined in the ginans. In small villages the executive powers were vested in the mukhi, and it was only on important matters that he summoned a meeting of the elders.
Pir Sadruddin also visited Punjab and Kashmir to build prayer-halls for the followers of Pir Shams, and also built a mausoleum of Pir Shams in Multan. His next visit to Patan, Gujrat was noted for giving a new life to the early unknown Khojas converted by Pir Satgur, whose condition since the time of giving up the Hinduism was yet unchanged. He breathed a new life into the dead class of these Khojas and brought them within the fold of new emerging Khoja community. It must be known that the new converts during the period of Pir Satgur were yet crude in their knowledge on Islam and Ismailism. No Ismaili dai is reported to have continued the mission after him during pre-Muslim era in Gujrat. The setback was due to the split of the Nizaris and the Must'alians in Egypt, resulting the Indian mission ignored for more than two centuries. Pir Sadruddin was the next dai to have launched his fresh mission in Gujrat when two to three generations of the original converts of Pir Satgur had passed away, and the third generation was almost more Hindus and less Muslims. They were getting the inspiration of the Satpanth from the old legends and miracles. Pir Sadruddin visited the different villages in Gujrat and also initiated them afresh on his own method and gave them a new lease of life and included them in the new emerging Khoja community.
Pir Sadruddin returned to Sind after a long journey. His principal area of activity certainly radiated from a base at Uchh, where he supervised the mission works.