19 July 1905 : Announcement by lord Curzon.
07 August 1905 : Resolution of boycott passed in the Town Hall of Calcutta.
16 October 1905 : Partition of Bengal in effect.
The population of Bengal at the time of partition was 7 crore 85 lakh, at that time Bihar and Orissa were included in Bengal. Assam was separated from Bengal in 1874 (governor was Lord Mayo). Lord Curzon gave the reason of administration inconvenience for the partition of Bengal but in reality the reason was political. Bengal at that time was the focal point of national movements and Bengali's had strong political awareness, to curb which Curzon tried to partition Bengal.
On 19 July 1905, decision of partition was declared. On 07 August 1905 at historical meeting at Townhall of Calcutta, the Swadeshi movement was declared and the historical boycott movement was passed. On 01 September 1905, government declared that partition of Bengal would be effected from 16 October 1905.
On 16 October 1905, Bengal was divided into East and West Bengal. East Bengal included Assam, Rajsahi, Chittagong and Dhaka and Dhaka was made its capital, the population was 3 crore and 10 lakh (Muslims: 1 crore and 80 lakh). West Bengal included Bihar, Orissa and Calcutta and Calcutta was made its capital, the population was 5 crore and 40 lakh (Muslims: 90 lakh).
On 16th October, black day/sorrow day was observed throughout Bengal. The declaration of partition of Bengal created such a strong political storm that it brought people and political leaders of different view on same platform. Vande Matram became national song overnight and became mantra for national movement. S.N. Bannerjee emerged as a major leader in anti partition movement. At this time Rabindra Nath Tagore wrote 'Rakhi Sangeet' and 'Amar Sonar Bangla'. 16th October was observed as Raksha Bandhan Day.
On 16th October, black day/sorrow day was observed throughout Bengal. The declaration of partition of Bengal created such a strong political storm that it brought people and political leaders of different view on same platform. Vande Matram became national song overnight and became mantra for national movement. S.N. Bannerjee emerged as a major leader in anti partition movement. At this time Rabindra Nath Tagore wrote 'Rakhi Sangeet' and 'Amar Sonar Bangla'. 16th October was observed as Raksha Bandhan Day.