Letter of Tansar
The Letter of Tansar was a 6th-century Sassanid propaganda instrument that portrayed the preceding Arsacid period as morally corrupt and heretical ( to Zoroastrianism ) , and presented the first Sassanid dynast Ardashir I as having "restored" the faith to a "firm foundation . " The letter was simultaneously a declaration of the unity of Zoroastrian church and Iranian state , "for church and state were born of the one womb , joined together and never to be sundered . " 
<triplet> Letter of Tansar <subj> Zoroastrianism <obj> main subject <triplet> Sassanid <subj> Arsacid period <obj> replaces <subj> Zoroastrianism <obj> religion <subj> Ardashir I <obj> founded by