Explanation:

The Swadeshi Movement had its genesis in the anti-partition movement which was started to oppose the British decision to partition Bengal.
The Government’s decision to partition Bengal had been made public in December 1903. The official reason given for the decision was that Bengal with a population of 78 million (about a quarter of the population of British India) had become too big to be administered. This was true to some extent, but the real motive behind the partition plan was the British desire to weaken Bengal, the nerve centre of Indian nationalism.
This it sought to achieve by putting the Bengalis under two administrations by dividing them (i) on the basis of language (thus reducing the Bengalis to a minority in Bengal itself as in the new proposal Bengal proper was to have 17 million Bengalis and 37 million Hindi and Oriya speakers), and (ii) on the basis of religion, as the western half was to be a Hindu majority area (42 million out of a total 54 million) and the eastern half was to be a Muslim majority area (18 million out of a total of 31 million).
Trying to woo the Muslims, Curzon, the viceroy at that time, argued that Dacca could become the capital of the new Muslim majority province, which would provide them with a unity not experienced by them since the days of old Muslim viceroys and kings. Thus, it was clear that the Government was up to its old policy of propping up Muslim communalists to counter the Congress and the national movement.