Amanullah Khan introduced the Afghan tricolour in 1928 as part of his modernization program, but his reforms were far from universally accepted. The next year, a Tajik rebel named Bacha-i-Saqao (“Son of a Water Carrier”) usurped the throne and installed a new reactionary government.
Sources are conflicted about what flags he used during his brief rule. Some say he restored the old 1919-1928 flag while others say he adopted this unusual red-black-white tricolour, allegedly based on colours used by the Mongols in the 13th century. The tricolour also looks suspicious similar to a flag attributed to Abdul Rahim’s largely autonomous government in Herat, which was black-red-white with a white crescent in the centre. And that flag may have actually been the flag of Purdel Khan, a former supporter of Bacha-i-Saqao who led a Tajik revolt in 1930. It’s difficult to sort it all out, and the lack of pictures of flags from this very short period doesn’t help any.