The word “azulejo” (glazed tile) comes from the Arabic word “azzelij“, meaning “little polished stone” – the word in Portuguese has nothing to do with “azul” which means “blue”, in fact it is true that there are many blue “azulejos” which explains this confusion.
The Arabs brought them to the Peninsula, the Portuguese started using them because D. Manuel, king of Portugal, appreciated their beauty during his visit to Spain. He decided to build his Palace (Palácio Nacional de Sintra) using imported tiles from Seville.
The use of tiles in facades became popular in the second half of the XIX century, standard-pattern tiles were cheap, resistant and capable of controlling temperature in homes.
In the north of the country, tiles were traditionally bigger, had a pronounced relief and used the contrast between light and shade.