As Salaam Alaykum Wa Rahmatullahi Wa Barakatuhu
It is generally accepted that the Arabic alphabet developed from the script used for Nabataean, a dialect of Aramaic used in northern Arabia and what is now Jordan during roughly the thousand years before the start of the Islamic era. It seems apparent that Syriac also had some influence on its development. The earliest inscription that has been found that is identifiably Arabic is one in Sinai that dates from about A.D. 300. Another Semitic script which was in use at about the same time and which is found on inscriptions in southern Arabia is the origin of the alphabet now used for Amharic, the official language of Ethiopia.
In the countries that use the Arabic alphabet, on the other hand, calligraphy has continued to be used not only on important documents but for a variety of other artistic purposes as well. One reason is that the cursive nature of the Arabic script and certain of its other peculiarities made its adaptation to printing difficult and delayed the introduction of the printing press, so that the Arab world continued for some centuries after the time of Gutenberg to rely on handwriting for the production of books (especially the Quran) and of legal and other documents. The use of Arabic script has therefore tended to develop in the direction of calligraphy and the development of artistically pleasing forms of hand lettering, while in the West the trend has been toward printing and the development of ornamental and sometimes elaborate type faces.
At the start of the Islamic era two types of script seem to have been in use -
both derived from different forms of the Nabataean, alphabet. One was square and angular and was called kufic (after the town of Kufa in Iraq, though it was in use well before the town was founded). It was used for the first, handwritten copies of the Quran, and for architectural decoration in the earliest years of the Islamic Empire.
Have more of information at this link:
http://www.islamicity.com/mosque/ihame/Ref3.htm
Peace be upon you.
Allah Hafiz
Sister Fatima
__________________