The Partition of Bengal, implemented by Lord Curzon in 1905, was a significant event in the history of British India. It aimed to divide the province of Bengal into two separate entities - Bengal and Eastern Bengal and Assam. This decision was met with widespread opposition and protests from the Indian nationalist movement, as it was seen as a deliberate attempt to divide and weaken the unity among the Indian population. The partition was eventually ended in 1911 when King George V abrogated Curzon's Act at the Royal Darbar in Delhi.

The reasons behind the partition were primarily political and administrative. Lord Curzon believed that Bengal had become too large to be effectively governed by a single administration. He argued that dividing the province would lead to better governance and administration. However, there were deeper motivations behind this decision. The British government was concerned about the growing influence of the Indian nationalist movement, which had gained momentum in Bengal. By dividing the province, they hoped to weaken the nationalist movement and prevent any unified resistance against British rule.

However, the partition had severe social and economic consequences. It sparked widespread protests and boycotts, led by prominent Indian leaders such as Rabindranath Tagore and Surendranath Banerjee. The Indian nationalist movement saw the partition as a deliberate attempt to divide the Hindu and Muslim communities, as Eastern Bengal had a Muslim majority. This led to communal tensions and violence between the two communities.

The partition also had economic implications, as Bengal was a prosperous region with a thriving textile industry. The division disrupted the economic stability of the region and led to a decline in trade and commerce. The protests and boycotts organized by the nationalist movement had a significant impact on the British government, who eventually decided to reverse the partition.

In 1911, during the Royal Darbar in Delhi, King George V announced the annulment of Curzon's Act and the reunification of Bengal. This decision was seen as a concession to the demands of the Indian nationalist movement and an acknowledgment of the failure of the partition policy. The reunification of Bengal was welcomed by the Indian population and marked a significant victory for the nationalist movement.

In conclusion, the Partition of Bengal implemented by Lord Curzon in 1905 lasted until it was ended by King George V at the Royal Darbar in Delhi in 1911. The decision to partition Bengal was met with widespread protests and opposition, leading to its eventual reversal. The annulment of the partition marked an important milestone in the Indian nationalist movement's struggle against British rule.