The leader of the mensheviks was

Julius Martov or L. Martov (Ма́ртов; real name Yuliy Osipovich Tsederbaum (24 November 1873 – 4 April 1923) was a Russian politician who became the leader of the Mensheviks in early 20th-century Russia. [1] According to his sister and fellow Menshevik, Lydia Dan, Martov had an 'inexhaustible charm that attracted people. As a result, some commented it was frequently difficult to record why they followed him, and he confessed himself that 'I have the nasty privilege of being liked by people' He was an old friend and mentor of Leon Trotsky. Trotsky later described him as the 'Hamlet of Democratic Socialism'. Vladimir Lenin later confessed in 1921 that his single greatest regret was 'that Martov is not with us. What an amazing comrade he is, what a pure man.

There's no attachment.