Answer:
Marat was a French journalist who suffered from a deteriorating skin disease that obliged him to spend most of his time inside a bathtub. However, this did not stop him from being one of the most respected voices among the radical groups of the revolution.
He made such claims because he was, along with Robespierre, the most noteworthy radical figure of the Revolution. Marat actively called for the murder of the King and the royal family, and the murder of all of the nobles and political prisoners who supported the king and the Ancient Regime.
In the end, he was successful because the royal family was beheaded, as well as many political prisoners. However, he was himself killed by a loyalist peasant, who stabbed him to death while he was on his bathtub.