There was, however, a more serious cause for the decline of the power of Portugal than the absolutism of the Crown, the want of patriotism of the nobility, or even than the corruption of the officials, and that was the rapid depopulation of the country. The Alemtejo and Algarves had never been thoroughly peopled, for the devastations caused by the Moorish wars could not be easily repaired; and, though the exertions of Diniz “the Labourer” had made the Beira the garden of the whole Iberian peninsula, the part of the kingdom to the south of the Tagus had remained either in the hands of the military religious orders or split up into large feudal estates. The great discoveries at the end of the fifteenth and the beginning of the sixteenth centuries largely checked the natural increase of population. Not only did the bulk of the young men gladly volunteer to man the fleets and serve in the armies in India and the East, but whole families emigrated to Madeira, and after 1530 to Brazil. The Portuguese are essentially an adventurous nation, fond of travelling and full of enterprise, and no difficulty was found in manning the great Indian fleets and recruiting the armies of Alboquerque and his successors. Of the thousands who flocked to Asia, but few ever returned. The incidents of perpetual warfare, and the noxious climate, killed off most, and of those who survived, many married native women and settled down in India. Even of the people who did remain in Portugal, few remained in their native homesteads engaged in agriculture; most crowded into Lisbon, where the necessities of the Eastern trade afforded work for all. The capital trebled its population in eighty years, in spite of its most unsanitary condition and the periodical pestilences which ravaged it. The king, the nobles, and the military orders were, however, quite undisturbed by this extensive emigration and rapid depopulation, for their large estates were much more cheaply cultivated by African slaves, who had been imported in such numbers that the Algarves was almost entirely populated by them, and in Lisbon itself they out-numbered the free men by the middle of the sixteenth century. In this respect the condition of Portugal resembled that of Italy at the time of the decline of the Roman Empire, as the wealth of Lisbon resembled that of Imperial Rome, while the utter corruption and oppression of the officials in the Indian settlements resembled only too closely the peculation and corruption of the Roman proconsuls and procurators.