Derived from the Aramaic Nabataean alphabets, the written form of Arabic existed prior to Islam. However, the calligraphically rendered Arabic scripts have been progressively developed along with the rise of Islam, from the early 7th century onward.  As the divine message of the Qura'an spread, calligraphy's main function has evolved into artistically recording and preserving the new revelation, where scribes, and later calligraphers. became committed to beautify, balance, and perfect their product in a way worthy of God's own words. Calligraphy had to turn into a disciplined profession, while its art became intertwined with science and spirituality. It was no surprise for the Islamic legend to have produced a popular saying such as “calligraphy is the geometry of the soul expressed through the body”.​
 

Throughout the early stages, numerous revisions were required to finalize the structure of the alphabet and its vocalization. The most important of these revisions were the contributions of Abul-Aswad Al-Du'li (d. 688) and Al-Khalil ibn Ahmad Al-Farahidi (d. 786) in devising and refining the system of the points and other diacritical signs (An-Nuqaat wal Harakat). Tracing the development of the Arabic scripts from the beginning, one cannot find a linear pattern. As Islam spread east and west, derivatives and styles of many scripts were developed simultaneously across the vast geography and became reflections of a diversity of cultures and localities. Historical references indicate that the script used in the first written Qura'an was “Jazm”, which may have been scribed by Zaid ibn Thabit and released during the caliphate of Uthman ibn Affan (644-656). Jazm came in different styles representing the birth regions such as the Hiri and Anbari in Iraq; and Makki and Madani in the Arabian desert. In addition to Jazm, many other scripts were developed throughout the birth regions and elsewhere. Some were popular to have continued and evolved into something else such as the Ma'il, which is considered the predecessor of the Kufi script, while other less popular scripts such as the Mukawwar, Mubsoott, and Mashq discontinued after some time.

​
A​s the Islamic state developed and expanded, a new group of scripts were developed to meet the rising secular functions, and face the increasing demand on the administrative and commercial correspondence. According to Safadi (1992), two of the star Umayyad calligraphers in Damascus were credited for their historical contributions, Qutba Al-Muharrir was credited for developing and improving the early secular cursive scripts such as the Tumar, Jalil, Nisf, Thulth, and Thulthain. He was also credited for writing the magnificent Jalil on the Mihrab section in the Prophet's Mosque in Madina. The second famous calligrapher of this era was Khalid ibn Al-Hayyaj, the official scribe of the Caliph Al-Waleed ibn Abdul Malik (705-715) whose father, Abdul Malik ibn Marwan, commissioned, during his reign, the first monumental Islamic achievement in architecture and calligraphy; Masjid Qubbatul-Sakhra or the “Dome of the Rock” mosque, which was completed around 690 in Jerusalem. Al-Hayyaj is also credited for scribing many large Qura'ans in Tumar and Jalil. These scripts were defined by the size of the pen by which they were written. The Tumar served as the core standard, where the height of its horizontal stroke is equal to twenty-four hairs from a horse's tail lined up together.  Nisf, Thuluth, and Thulthain, therefore,  refer to the half, third, and two-thirds of the Tumar respectively. Safadi states that a rival Arabic theory refers to the Nisf, Thuluth, and Thulthain as the ratio of straight strokes to curves in these scripts.


The Iraqi city of Kufa, which was established as a garrison depot around 640, gradually turned into a religious and cultural center. Many scribes were attracted to the right atmosphere where calligraphy flourished, and a new script was born. The Kufi script, which has its roots in the early Mai'l,  is a non-cursive, purely geometrical, and mostly ornamental type. Its development reflected the growth of a generation versed in calculus and geometry. The Kufi was a widely applicable script with the most derivatives and variants such as Almathfoor (plaited), Almazhoor (floriated), Almowarraq (foliated), Alma'qood (knotted), Almukhammal (superimposed), Almuraba' (squared), and many others. The Kufi script was also distinguished geographically as Mashriqi (Eastern) referring to a variety developed in Baghdad, and Maghribi (Western) referring to a variety developed in Qairawan in the far west of the Arabic region.  The Maghribi subsequently became popular in Northwest Africa and Andalusia, especially under the Aghlabid (800-909) and the Fatimids (910-1171). The Kufi script reached its summit at the end of the 8th century and continued to dominate the profession of copying the Qura'an until the cursive and more fluid scripts gradually replaced it.


By the eleventh century, only Thuluth , among the early cursive scripts, survived to be at the top of the list of the most popular six scripts called “Al-Aqlamu-s-Sitta” or the six pens, referring to the six most popular calligraphic styles at the time- Thuluth, Naskh, Muhaqqaq, Rihani, Riqaa', and Tawqi. Although Thuluth, Muhaqqaq, and Rihani were used to copy the Qura'an, it was the Naskh script that gained unrivaled popularity and dominated the Mushaf writing business. To the present day, Naskh still dominates all other scripts in the administrative and educational functions. The lettersets used in print and computers today are mainly based on Naskh and Kufi. The development of Riq'a and Tawqi, which were closely related to Thuluth, were attributed to Ibn el-Khazin (d. 1124).


For the next five centuries, and under the Abbasid dynasty (750-1258), Baghdad became the capital of the Islamic empire. It was called “Madinatu-s-Salam” or the city of peace. It was stable and highly developed to serve as the supreme cultural center of the world, where arts and sciences enjoyed their most productive and glorious times. It was in this era that calligraphy was revolutionized to become a field of study, where geometrical and aesthetic rules were introduced to standardize the scripts and elevate calligraphy to what was called “Al-Khatt ul-Mansoob” or the proportioned calligraphy. Three Iraqi calligraphers stood tall as giants in this development and subsequent refinements.  They were considered by all accounts the pillars on which the entire history of Arabic-Islamic calligraphy was built.  They were: Abu Ali Muhammad ibn Muqla (d. 940), Abul Hasan Ali ibn Hilal ibn el-Bawwab (d. 1024), and Yaqoot Al-Musta'ssimi (d. 1298). Most Islamic references agree that calligraphy's major geometrical guidline utilizing the rhombic dot was invented by Ibn Muqla, and completed, amended and refined with innovative techniques and practice by Ibn el-Bawwab and Al-Musta'ssimi. It was Yaqoot, according to Derman (1998), who came up with the idea of cutting the nib of the reed pen at an angle instead of straight across- an innovation that brought a great deal of elegance to calligraphy. It was also Yaqoot, according to Safadi (1992), who was depicted in a famous miniature painting when he sought sanctuary at the top of a minaret in Baghdad to finish his calligraphy practice while the city was being ravaged by the Mongol Armies in 1258. That was a concrete testimony for his discipline and commitment to his art.
Great achievement in calligraphy occurred under the Mamluks in Cairo (1250-1517) who were highly enthusiastic patrons of Islamic art. Outstanding calligraphers such as Muhammad ibn el-Wahid , Muhammad el-Muhsini, and Ibrahim ibn el-Khabbaz left many calligraphic masterpieces, especially in the form of the Qura'an illumination. The commitment of the Mamluks, and the descipline of the Ottomans after them left a strong legacy of classical tradition in calligraphy still alive in Cairo to this day.


Three other distinguished scripts were developed in Persia: The highly elegant and poetically flowing Ta'aleeq was derived from the little known Arabic script called Firamuz. Safadi (1992) stated that Ta'aleeq was developed by Taj-i-Salmani el-Isfahani in early ninth century, and later, refined and popularized by Abdul Hayy ul-Istarabadi. The second script was the Nesta'aleeq - a combination of Naskh and Ta'aleeq, which was attributed to Mir Ali Sultan el-Tabrizi (d. 1416), and perfected by Mir Imad el-Hasani (d.1615). This script was popular enough in Persia to become and continue to be the national script to the present day. The third script was the Shikasteh, which was mostly popularized by Darwish Abdul Majid el-Taliqani.


Other development of the Arabic scripts occurred further east such as the Hirati script in Afghanistan, Behari and Zulf el-Aroos in India, and Sini in China.
The shining star of calligraphy ascended again over the Islamic empire during the Ottoman reign, especially during its most stable era (1500-1923). For more than four centuries, calligraphy reached perfection at the competent hands of a long line of outstanding masters of Istanbul. They did not only refine the known scripts and elevate their qualities to their zenith, but also invented more scripts such as Diwani, Jeli Diwani, Tughra'a, and Siyaqat. At the top of this remarkable line of calligraphers were Shaikh Hamadullah Al-A'masi (1429-1520), Alhafuth Othman (1642-1698), Mustafa Raqim (1758-1826), Sami Afendi (1838-1912), Shawqi Afendi (1829-1887), and Muhammad Al-Yasari (d.1798). The last three giants were Mustafa Halim (d.1964), Nejmiddin Okyay (d.1976), and Hamid Aytac Al-Amadi (d.1982). The dazzling calligraphy we know today would have not been possibly achieved if it were not for the brilliance and dedication of those masters.

​
In conclusion, it can be stated that there is no doubt that the core of the classical tradition in Arabic-Islamic calligraphy has been primarily attributed to two highly influential schools: The early Baghdadi school (900-1300), and the later Ottoman school (1500-1900). Therefore, It can wisely be said that Arabic-Islamic calligraphy was born and grew up in Baghdad, but matured in Istanbul.