Tiles were introduced to Iberia by Moors from North Africa. The word azulejo comes from the arabic for 'little stone'. This probably referred originally to mosaics. Most of the Moors in Iberia belonged to the Sunni branch of Islam which outlawed images of living things. It has been sugessted that this is why tiles from this period use geometric patterns rather then the organic floral patterns of the Portuguese. The Moors left behind many exmaples of tiles when they were expelled from Portugal. The fashion for tiles and white washed walls continued without them.
The tiles shown above are not from Moorish times, but to this day the taste for geometric patterns remains.