Whether he had public duties entrusted to him or not, Martinez de la Rosa seems then to have stayed some time in London, studying the workings of the parliamentary system, the good fruits of which he, as Mirabeau had before him, found in his legislative career. There he printed, in 1811, his poem, Zaragoza, written in competition for the prize offered by the Central Junta, in celebration of the defence of that city in 1809, and there also he wrote several other poems. The one of Zaragoza seems not to have been reprinted in Spain till the publication of his collected poems in Madrid in 1833, and no adjudication ever was made on the compositions prepared at the suggestion of the Junta, but it is stated that the judges had unanimously agreed to confer on him the premium offered in the name of the nation. In 1811 the French armies had driven the assertors of national independence from all the other principal parts of Spain to Cadiz, and there the Cortes were convoked to meet. There then, Martinez de la Rosa returned, and though not yet of the age required by law to be chosen a Deputy, he took part in all the deliberations of the national councils, and was appointed Secretary to the commission on the freedom of the press. Meanwhile the siege of Cadiz was commenced by the French and pressed unremittingly; but the spirit of the defenders did not fail them. Martinez de la Rosa and Quintana continued their literary labours, and the former produced a comedy and a tragedy, both of which were received with much favour. The latter continues a favourite on the stage, on a subject well chosen from Spanish history, and entitled the ‘Widow of Padillia.’ To use his own words, “It was represented, for the first time, in July 1812, and in days so unfortunate, that it could not be produced even in the theatre at Cadiz, on account of the great danger from the bombs of the enemy, which had nearly caused, a little before, the destruction of the building, crowded at the time with a numerous audience. For this reason they had to erect a theatre of wood in another part of the city, at a distance from where the French artillery had directed their aim.” Shortly after this the siege was raised, and the French having again evacuated Madrid, the Cortes were convoked to assemble there, when Martinez de la Rosa was elected Deputy for his native city. He had throughout the struggle joined the most active members of the liberal party, Arguelles, Quintana and others, who, all honourable and patriotic characters, had acted in perfect sincerity in forming the Constitution of 1812, as it was called, which they hoped would secure the future freedom of the country.