On 13 May 1610, Queen Margaret attended Marie's coronation at Saint Denis. The following day, Henri IV was assassinated by the fanatic monk François Ravaillac and Marie de' Medici obtained the regency for their minor child. The regent was entrusted with various diplomatic roles, including the reception of foreign ambassadors at court, the celebrations for the future marriage of Louis XIII and in the Estates General in 1614, in which Margaret was charged with negotiating with clergy representatives. This was her last public assignment.