However, Jinnah did not join the League until 1913, when the party changed its platform to one of Indian independence, as a reaction against the British decision to reverse the 1905 Partition of Bengal, which the League regarded it as a betrayal of the Bengali Muslims. After vociferous protests of the Hindu population and violence engineered by secret groups, such as Anushilan Samiti and its offshoot Jugantar of Aurobindo and his brother etc., the British had decided to reunite Bengal again. Till this stage, Jinnah believed in Mutual co-operation to achieve an independent, united 'India', although he argued that Muslims should be guaranteed one-third of the seats in any Indian Parliament.