Overview
Reza Shah governed clothing as an instrument of state, and did it with unusual bluntness. Between the mid-1920s and 1936 Iranian men were required by law into European dress and a specific cap, and Iranian women were forbidden the veil — an attempt to change what a nation was by changing what it wore, enforced by police.
Key garments and style
The 1928 uniform dress law put men into European jacket and trousers and prescribed the Pahlavi cap, a peaked cloth cap whose brim was the point: it prevented the wearer from touching the forehead to the ground in prayer, so it was resisted as an attack on observance as much as on custom. In 1935 it was replaced by the European brimmed hat, which sharpened the objection.
The unveiling decree of January 1936 banned the chador and headscarf outright. Police removed veils in the street. For women who regarded covering as a religious obligation the effect was not liberation but house arrest, and many did not go out for years; for a smaller urban class it opened public life. Both things were true at once, which is why the period is still argued about.
Beneath the coercion, Western dress genuinely spread through the cities across the following decades, and Tehran had a fashion press and boutiques by the 1960s.
Transition
The 1979 revolution reversed the direction exactly, making covering compulsory where uncovering had been — the same instrument turned the other way.