This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Ahmad Sirhindi founded what is known as the Mujaddidi line of the Naqshbandi Sufi order in Mughal India, a documented new line distinct from simply continuing the order's existing practice unchanged, named after his own honorific title, Mujaddid Alf-i Thani, reviver of the second Islamic millennium. That title is documented as marking his reform work specifically at the turn of Islam's second thousand years by the Hijri calendar, a dated framing distinct from a reform claimed to apply at no particular moment.
His collected letters, the Maktubat, became a foundational text for that Mujaddidi line, a documented body of writing distinct from oral teaching alone, carrying his reform across Mughal India and later out into the wider Naqshbandi world beyond India's own borders. That the line takes its name directly from Sirhindi's own honorific, rather than from a place or an earlier teacher, is recorded as reflecting how closely the reform itself was identified with the specific reviver's role Sirhindi claimed for his own moment in Islamic history.
That a Sufi reformer's own honorific title, naming him reviver of Islam's second millennium, became the name of the entire line his reform founded marks the Mujaddidi line as a documented case where a movement took its lasting identity directly from the dated claim its founder made about his own historical moment.