The Arabic script descended from the Aramaic through the Nabataean and the neo-Sinaitic alphabets. After the Latin script, it is the most widely used form of alphabetic writing in the modern world. The Arab conquests of the 7th and 8th centuries ce brought the language and the script to the vast expanse of territory extending from India to the Atlantic Ocean. The Arabic alphabet was adapted, with some necessary modifications, to such diverse languages as the Slavic tongues, Spanish, Persian, Urdu, Turkish, Hebrew, Amazigh (Berber), Swahili, Malay, Sudanese, and others.

The Arabic alphabet probably originated at some time in the 4th century ce, but the earliest extant Arabic writing is a trilingual inscription—Greek-Syriac-Arabic—of 512 ce. The two principal types of Arabic writing, which developed quite early in the Muslim period, were the Kūfic, from the town of Kūfah in Mesopotamia, seat of a famous Muslim academy, and the naskhī, or Mecca-Medina script. Kūfic, a heavy, bold, and lapidary style, appeared toward the end of the 7th century ce. It was particularly suitable for writing on stone or metal, for painting or carving inscriptions on the walls of mosques, and for lettering on coins. Its letters are generally thick, squat, and unslanted. With the high development of Arabic calligraphy, Kūfic writing became an exceptionally beautiful script. From it there were derived a number of other styles, chiefly medieval, in North and Central Africa, Spain, and northern Arabia. Thereafter, it was virtually discontinued except for formal and monumental writing. Nevertheless, it was also used for writing precious manuscripts of the Qurʾān, many of which are extant today.

The naskhī style was from the very outset a more cursive form. It was always employed chiefly for writing on papyrus. In time, it evolved into innumerable styles and varieties, including the taʿliq, the riqaʿ, the divani, the thuluth, and the syakat, and became the parent of the modern Arabic writing.

Like other Semitic scripts, Arabic is written from right to left. Its alphabet contains 28 consonantal letters, 22 being directly derived from the Aramaic-Nabataean branch of the North Semitic alphabet and six being new additions; three of the letters—alif, wāw, and yāʾ—are also used as long vowels.

The written letters undergo a slight external change according to their position within a word. When they stand alone or occur at the end of a word, they ordinarily terminate in a bold stroke; when they appear in the middle of a word, they are ordinarily joined to the letter following by a small, upward curved stroke. With the exception of six letters, which can be joined only to the preceding ones, the initial and medial letters are much abbreviated, while the final form consists of the initial form with a triumphant flourish. The essential part of the characters, however, remains unchanged. On the whole, the evolution of the forms of the Arabic letters was the most rapid of all the branches of alphabetic writing.

Although the absence of vowel letters was not strongly felt in Arabic (as in Hebrew and other Semitic languages), for teaching purposes and for correct reading of the Qurʾān, the use of diacritical marks (including signs for short vowels, which are sometimes used in conjunction with the letters alif, wāw, and yāʾ) was introduced in Basra in the early 8th century. The practice was probably borrowed from the Syriac script. It not only provides vowel sounds but also distinguishes different consonants; diacritical points are also used as endings in the inflection of nouns and the moods of verbs. These marks—there are three of them—are written above or below the consonants (preceding the vowel), while a sign called sukūn indicates the absence of a vowel. Thus, there are, on the whole, a great number of diacritical points; these form a peculiar characteristic of this writing form.

Indian alphabets

The Aramaic alphabet was probably the prototype of the Brahmi script of India, the ancestor of all Indian scripts. The transmission probably took place in the 7th century bce. Adapting the Aramaic script to the Indo-Aryan tongue of India was by no means simple or straightforward. The shapes of many Brahmi letters show clear Semitic influence; moreover, the Brahmi script was originally written from right to left. It is obvious, however, that on the whole it was the idea of alphabetic writing that was transmitted and that the fully developed Brahmi writing was the outcome of the brilliant philological and phonological elaboration of the scientific Indian school.

During the 5th century bce the second of the prototypal Indian alphabets—the Kharosthi script—came into being in northwest India (which was then under Persian rule). Although the origin of Brahmi is still uncertain and hotly discussed, it is commonly accepted that the Kharosthi alphabet is a direct descendant from the Aramaic alphabet. Moreover, the direction of writing in Kharosthi script is as in Aramaic, from right to left, and there is also a likeness of many signs having similar phonetic value.

In the later centuries of its existence, Brahmi gave birth to eight varieties of script. Three of them—the early and late Maurya and the Sunga (Shunga)—became the prototypes of the North Indian subdivision of the Brahmi script in the 1st centuries bce and ce. Out of this North Indian subdivision there arose the Gupta, which was employed from the 4th to the 6th century ce and became the ancestor of the great majority of Indian scripts.

The western variety of the Gupta spread into eastern (or Chinese) Turkistan, where it was adopted for a number of languages, including Turfanian and the Tocharian languages, and where it strongly influenced the invention or revision of the Tibetan script (639 ce). There were two main offshoots of the Tibetan writing: the ’Phags-pa, adapted to the Chinese and Mongolian languages in 1272; and the Lepcha, which arose in the beginning of the 18th century.

Much more important was the Siddhamatrka script, developed during the 6th century ce from the western branch of the eastern Gupta character. The Siddhamatrka became the ancestor of the Devanagari, or Nagari, script (Sanskrit deva [“divine”], nāgarī [“script of the city”]), which is the script used for Sanskrit. It is, therefore, the most important Indian script. Consisting of 48 signs (14 vowels and diphthongs and 34 basic consonants), it is the common means of communication among the learned throughout India. The Devanagari developed in the 7th to 9th centuries and has remained since then essentially unaltered.

From the Devanagari writing as used in eastern India in the 11th century, there developed the proto-Bengali and the early Nepali, or Newari, scripts, from which the many scripts employed at present in northern India and Bangladesh descended (e.g., the Bengali, Oriya, Manipuri, Assamese, Gujarati, and Hindi scripts and the various Eastern Hindi local scripts).

In northwestern India several other scripts are employed. The Sarada script, a descendant of the western type of the Gupta character, originated in the 8th century and is still employed for Kashmiri. In addition, there are the several varieties of the Takri, used by the people living on the lower ranges of the western Himalayas; Dogri, used for a dialect of Punjabi; Landa, the national alphabet of Punjabi, which has many varieties and is used mainly by shopkeepers of Punjab and Sindh; and Gurmukhi script, the characters of the Sikh scriptures.

In South India, which is inhabited by peoples speaking Dravidian languages, several other scripts are used, of which Kannada, or Kanarese, Telugu, Grantha, Malayalam, Tamil, and Vatteluttu (“Round Script”) are the most important.

Long before the existence of the Gupta script, the Brahmi script had already begun its eastward movement. The Indo-Aryan migration in the 5th century bce to the island of Sri Lanka had set the stage there, and the earliest Brahmi inscriptions in Sri Lanka can be dated to the 3rd century bce. Most dramatic of all, however, was the expansion of Buddhism from India into what are now Sri Lanka, Myanmar, Thailand, Cambodia, Laos, Vietnam, Malaysia, and Indonesia. This was a peaceful movement; its “soldiers” were Buddhist monks, political independents who built an empire founded on the cultural and spiritual community of peoples. Among their many achievements, these monks brought into being offshoots from the Brahmi script, principally from its South Indian varieties, throughout the vast extent of territory from India itself to the Philippines. Thus arose the many scripts of Southeast Asia, from the Cham writing of Cambodia to the Kavi character of Java and its Sumatran offshoots and the Tagalog writing of the Philippines.

All these Indian and Southeast Asian scripts involve types of semi-syllabaries rather than alphabets. They consist of vowels and diphthongs and basic consonants (i.e., consonants followed by a short a); there are no pure consonants (i.e., consonants written by themselves).