Meanwhile the Company had decided to consider Bombay as "an independent settlement, and the seat of the power and trade of the English in the East Indies." But a variety of causes set back the development of the city, notably the prevalence of plague and cholera due to the silting up of the creeks that divided its component islands; and it was not till after the amalgamation of the old and new companies in 1708 that the governor's seat was transferred from Surat to Bombay. In 1718 the city wall was completed; settlers began to stream in, especially from distracted Gujarat; and a series of wise administrative reforms increased this tendency until in 1744 the population, which in 1718 had sunk to 16,000, had risen to 70,000. Meanwhile the Mahratta conquest of Bassein and Salsette (1737-1739) had put a stop to the hostility of the Portuguese, and a treaty of alliance with the Siddis (1733) had secured a base of supplies on the mainland. The French wars of 1744-1748 and 1756-1763 led to a further strengthening of the fortifications; and the influx of settlers from the mainland made the questions of supplies and of the protection of trade from piracy more pressing. The former was in part settled by the acquisition of Bankot (1755) as a result of an alliance with the peshwa, the latter by the successful expedition under Watson and Clive against Vijayadrug (1756). During this period, too, the importance of Bombay as a naval base, long since recognized, was increased by the building of a dock (1750), a second being added in 1762. The year 1770 saw the beginning of the cotton trade with China, the result of a famine in that country, the Chinese government having issued an edict commanding more land to be used for growing grain. This, too, was a period of searching reforms in the administration and the planning and building of the city; the result being a further immense growth of its population, which in 1780 was 113,000. This was still further increased by the famine of 1803, which drove large numbers of people from Konkan and the Deccan to seek employment in Bombay. A great fire broke out in the fort in the same year and caused enormous loss; but it enabled the government to open wider thoroughfares in the more congested parts, and greatly stimulated the tendency of the natives to build their houses and shops outside the walls of the fort in what are now some of the busiest parts of the city.