Matters eventually came to a head with the resignation of the War Minister, the
Baron de Bonfim. The radical clubs and the National Guard feared that this would allow Queen
Maria II to appoint a new cabinet that would reimpose the Constitutional Charter of 1826. This, they agreed, would be a betrayal of the
September Revolution. On 4 March 1838 the civil governor of Lisbon and commander of the National Guard, Francisco Soares Caldeira, invited the corps commanders to sign a petition asking the Queen not to appoint any ministers who were not loyal to the values of the September Revolution. The following day the battalion sent a statement to the Constituent Congress announcing their loyalty to the Queen and their lack of confidence in the government. On 8 March it became known that on the previous day the Queen had dismissed Soares Caldeira and replaced him as civil Governor of Lisbon with
António Bernardo da Costa Cabral. In protest, on the morning of 9 March, the insurrectionary Guard battalions under França occupied the Arsenal building. Government troops under the Baron de Bonfim were ordered from the
Largo da Estrela down into the city, where they surrounded the Arsenal. To avoid fighting both sides agreed to talks. ==The Convention of Marcos Filipe==