With the penetration of Islam into Iran (Persia), the early Arabic Kufic script was adopted by Iranians. The adoption evolved into the first form of Iranian calligraphy called Naskh. As a result, of the borrowed Kufic script, some Arabic words entered the Farsi language. This language would eventually be known as Farsi-e-Dari.
For a century, the Kufic script did not contain dots or accents, making it difficult for Iranians to read the language. In future years the accents and dots were invented by Abol-Asvad and Naser-Asen.
For three centuries, over 20 scripts were used in the Persian language marking this the period of manuscript anarchy in Persia.
Between 9-10AD, Ibn-e- Moqleh, a famous manuscript writer of the Quran, innovated new calligraphy rules limiting their variations to six styles. These styles are known as Thulth, Naskh, Reyhan, Mohaggeg, Towgi, and Rega. The famous six, as they are called, remain prevalent in calligraphy today due to their perfect form.
Among the six styles, Taliq and Nataliq scripts were created by Persian calligraphers in 14th century AD. While Taliq was seldom used, Nataliq, created by Ali Tabrizi, became a prominent form of Persian calligraphy combining curvatures of both Taliq and Naskh. Nastaliq has flourished in Iran in the last seven centuries with its twelve principles. These principles are: boundary, balance, proportion, combination, surface, rotation, wide surface, narrow surface, ascent, descent, grace, and dignity. The last two principles (grace and dignity) are considered the highest level of human excellence and cannot be achieved without spiritual involvement in the art of calligraphy.