The 22 March Circle was an anarchist circle based in Italy, Rome during the "Years of Lead". The circle was founded in 1969 by Pietro Valpreda, a former member of Giuseppe Pinelli's Milan group, who saw the group as too moderate. Valpreda was an advocate of violence, promoting the use of bombings and terrorism; Pinelli was a peaceful anarchist, and kicked Valpreda out of the group. Valpreda's circle had seven members, namely himself, Mario Merlino, Salvatore Ippolito (an informant), Emilio Borghese, Emilio Bagnoli, Roberto Gargamelli, and Enrico Di Cola, and its actions bore little relevance, apart from a single anti-Vietnam War protest. Following the Piazza Fontana bombing of 1969, the Italian government arrested the circle's members, suspecting anarchists of being behind the attack. However, they realized that such a small group would not have the capability to carry out such an attack, and its members were acquitted in 1972.