Complex sentence: It was there that he was initiated into the revolutionary movement.He along with Bhagat Singh and Sukhdev started a study circle on the model of Russian Revolution.He was a leading member of HSRA under the banner of which he continued his revolutionary activities.
Split into simpler sentences: It was there that he was initiated into the revolutionary movement.He along with Bhagat Singh and Sukhdev started a study circle on the model of Russian Revolution. Later he became a leading member of HSRA under the banner of which he continued his revolutionary activities.