[Sidenote: Economic backwardness.] As was natural in such an age of disorder, commerce and industry did not flourish. With the rise of the towns a beginning was made, and at least one town, Santiago de Compostela, seems to have attained to some industrial importance. Commerce was hampered by innumerable obstacles, such as the depredations of foreign enemies and robber lords, the duties which had to be paid to the king, and the tolls which were collected by the lords at highways, rivers, or bridges within their lands. Stock-raising and agriculture and the production of the bare necessities of life were the principal occupations. Even these suffered, not only from the raids of the Moslems and the nobles, but also from the extreme weight of taxation, which was all the worse in that it was levied at the caprice of the king, lord, or churchman collecting it. The state of misery was so great that it is not surprising that famine and epidemics harassed the people. [Sidenote: Ignorance and superstition.] [Sidenote: Innovations in architecture.] In general culture, too, there was a decline to an even lower level than that of the Visigothic period. Churches and monasteries maintained something of the old intellectual traditions, and their schools were almost the only resort for an education. Latin continued to be used in literature and in official documents, but was already acquiring the new forms which were to pave the way to the various Romance tongues of later days. The age was one of superstition, which made itself manifest, as in other parts of Europe, even in judicial procedure. The tests of wager of battle (or a duel between litigants), the hot iron, and boiling water were all used to determine innocence or guilt, in the belief that God would intervene on the side of the man whose cause was just. Poverty and danger led men to live in groups, thereby introducing a fresh departure from Roman individualism. In the towns life more nearly resembled the Roman type. In architecture this period marked the introduction of the buttress in some of the churches. Naturally, it was an age of the building of castles and walls, although the materials used were perishable. Most edifices were of wood, for in that day Spain was covered with forests in regions where they no longer exist. The burning of villages in times of war, especially during the Norman invasions, led to an exchange from the wooden roof in church building to one of non-combustible material of industrial manufacture. _Kingdoms of Navarre, Aragon, and Catalonia_ [Sidenote: The Christian reconquest of Catalonia.]