In the book Tale of Two Cities who is monsieur gabelle?

Gaspard's young son is run over by the Marquis' carriage as it speeds through town. In response, the Marquis flicks Gaspard a coin, showing a complete disregard for Gaspard's son's life. Gaspard later assassinates the Marquis, and is then captured and killed himself. Support for Gaspard grows throughout these events--these three deaths are the beginning of the French Revolution.