His selection to the role of Patriarch was held in the traditional way: The Council of Bishops of the Russian Orthodox Church (knowing in advance the will of Mikhaill Romanov[1]) pointed to three candidates, of whom the Tsar could choose.

Enthronement of the new Primate of the Russian Orthodox Church was held, also in keeping with tradition, in the Cathedral of the Dormition of the Mother of God in the Kremlin[2] in Moscow on 6 February 1634.

Also, Joasaphus published the so-called Требник (Trebnik, or book of prayers) with a supplement of Philaret's resolutions and decrees.

Parsley also points out that the relatively short period of office of the patriarch by Joazafa results in the obfuscation of his achievements by the much more well-known and strong personalities of the two other seventeenth-century Russian Orthodox Church superiors: Filaret and Nikon.

At the same time the authors of works devoted to Josaphus give it a raw ascetic, pious and humble man.