Etymology: < Italian montambanco, montimbanco (late 17th cent.), contracted form of monta in banco (1598 in Florio), lit. ‘mount on bench’ ( < monta imperative of montare mount v. + in on + banco bench: see bank n.2), with reference to the raised platform used by itinerant salesmen.1.a. An itinerant charlatan who sold supposed medicines and remedies, freq. using various entertainments to attract a crowd of potential customers. Later also (more generally): an itinerant entertainer. Now chiefly hist.
b. gen. A charlatan, a person who falsely claims knowledge of or skill in some matter, esp. for personal gain; a person who pretends to be something he or she is not, in order to gain prestige, fame, etc. Formerly used freq. of corrupt clergy and others assuming false piety or religiosity. (OED)
"As for the British Muslim “leaders,” whom, exactly, did they lead? They were leaders without followers, mountebanks trying to make careers out of her brother’s misfortune. For a generation, the politics of ethnic minorities in Britain had been secular and socialist. This was the mosques’ way of getting religion into the driver’s seat."
- Salman Rushdie, "The disappeared: How the fatwa changed a writer's life", 17 September 2012 The New Yorker