historians do not agree on a specific date for the establishment of direct arab-islamic rule over iran (persia), even when such rule was exercised by local families of turkish or persian origin. what is known is that the islamic conquest of persia began during the reign of caliph abu bakr al-siddiq and reached its height under caliph omar ibn al-khattab. this period ended with the fall of the sasanian empire and the death of its last ruler, yazdegerd iii, in 651 ce (30 ah).
after this, iran came under the rule of the caliphs, followed by the umayyad and abbasid dynasties, with arab governors and rulers administering the region. over time, arab political influence gradually declined. by the early nineteenth century, governance had become largely persian, although arab cultural and intellectual influence remained strong. arabic continued to be widely used in religion, science, and administration in many important fields.
a major turning point in iran’s political and religious history occurred in 1501 with the establishment of the safavid dynasty. shah ismail safavi declared twelver shi‘ism the official religion of the state, replacing sunni islam. this decision marked the formation of a distinct political and religious identity for iran, even though islam remained the official state religion.
linguistic studies show that arabic vocabulary makes up a significant portion of the persian language, estimated at around half of its total vocabulary. several attempts were made to reduce arabic influence in persian, most notably by reza shah, the founder of the pahlavi dynasty and the father of the last shah. however, these efforts were largely unsuccessful.
linguistic change proved difficult because thousands of arabic roots are deeply embedded in persian religious, legal, administrative, philosophical, and literary traditions. many arabic words are not merely borrowed terms but have become integral to persian grammar, structure, and style. centuries of arabic use as the language of science and religion also produced a vast cultural and literary heritage. removing arabic vocabulary would therefore sever persian from centuries of tradition and written history.
such changes are difficult to impose on writers, scholars, and the general public. reza shah attempted to promote linguistic reform through institutions such as the iranian academy and later the academy of persian language and literature, which aimed to create persian alternatives for foreign and arabic terms. these initiatives failed to achieve lasting success because language reform cannot be enforced by academies alone; it depends on how people actually speak and write.
many of the proposed alternatives remained limited to official and elite circles, while the general public continued to reject them. arabic words in persian are neither phonetically nor morphologically foreign. having adapted to persian poetic meters and usage, they are often shorter, clearer, and easier than artificially created substitutes. as a result, they continue to be widely used in everyday language.
attempts to replace thousands of words in newspapers, books, and educational materials created confusion and placed an extra burden on readers. many writers therefore preferred to return to the traditional vocabulary that was already well understood. ironically, despite his efforts to glorify “persian identity” and promote slogans such as “pre-islamic iran,” reza shah himself relied heavily on arabic vocabulary in his speeches and writings.
the resistance to forced persianization was also strengthened by the presence of three major minority groups: turks, kurds, and arabs. these communities opposed such projects out of concern that their own languages and identities would be targeted next. their resistance was driven by political and identity-based reasons rather than purely linguistic ones. as a result, the project of linguistic “cleansing” remained largely ideological and did not bring about real change in the persian language or its daily usage.
in contrast, persian influence on arabic is relatively limited and consists of only a few hundred words, such as diwan (council), dustur (constitution), khandaq (trench), bustan (garden), tasht (basin), tazaj (fresh), sijil (register), and band (paragraph). however, a greater number of persian words can be found in gulf arabic dialects, particularly in iraq, kuwait, and along the western coast of the arabian gulf.