I. He heartily thanks the Emperor for what he has done, and asks him to complete the work in any way he can.
If we should seek to reward your Majesty's glorious resolution in defence of the Faith with all the praise that the greatness of the issue demands, we should be found unequal to the task of giving thanks and celebrating the joy of the universal Church with our feeble tongue. But His worthier recompense awaits your acts and deserts, in whose cause you have shown so excellent a zeal, and are now triumphing gloriously over the attainment of the wished-for end. Your clemency must know therefore that all the churches of God join in praising you and rejoicing that the unholy parricide has been cast off from the neck of the Alexandrine church, and that God's people, on whom the abominable robber has been so great a burden, restored to the ancient liberty of the Faith, can now be recalled into the way of salvation by the preaching of faithful priests, when it sees the whole hotbed of pestilence done away with in the person of the originator himself.
Now therefore, because you have accomplished this by firm resolution and steadfast will, complete your tale of work for the Faith by passing such decrees as shall be well-pleasing to God in favour of this city's Catholic ruler, who is tainted by no trace of the heresy now so often condemned: lest, perchance, the wound apparently healed but still lurking beneath the scar should grow, and the Christian laity, which by your public action has been freed from the perversity of heretics, should again fall a prey to deadly poison.
Source: Letters (New Advent)