'The period from the middle of the Safavids to the time of Vahid Bihbahani was the period of the dominance of the Akhbari school in 12er Shiaism. The doctrines this school are described further in this book (pg 222). Although this controversy had begun as a comparatively minor disagreement on a few points, it grew eventually into a bitter and vituperative dispute culminating in Bihbahani's declaration that Akhbaris are infidels (kuffar).
At first, the Akhbaris predominated in the shrine cities of Iraq, but it was Bihbahani who, at the end of the 18th century, reversed this and indeed, completely routed the Akhbaris of Karbala and Najaf. South Iraq, Bahrain, and a few cities in Iran would remain Akhbari strongholds for a few more decades but eventually the Usooli triumph was complete and only a handful of Shia ulema have remained Akhbari to the present day.
The results of Bihbahani's victory for 12er Shiaism were to be far reaching. By his takfir against the Akhbaris, Bihbahani continued in the work of Majlisi in narrowing the field of orthodoxy in 12er Shiaism. But where Majlisi had acted to exclude Sufism and philosophy which were at the periphery of the concerns of most of the ulema, Bihbahani brought the threat of takfir into the central field of theology and jurisprudence, where previously only ikhtilaaf had existed. Bihbahani was now to exclude by takfir all who disagreed with him with the principles of aql and ijtihad as sources of law. This paved way for great increase in the power and influence of the mujtahids in the Qajar times and for the evolution of the concept of 'marja taqlid' (see pg 204). Bihbahani's importance was acknowledged by later generations of shia ulema who referred to him as 'Muassis' (founder of Usoolism), Ustad e Kull (Universal), Murawwij (Propagator) and the Mujaddid (Renewer) of the 13th Islamic century. His achievement would set the tone and direction of Shia development to the present day.