To be found at the end of King Alfred's translation of 'On the Consolation of Philosophy'. (~9th c.)
O Lord God Almighty, Maker and Ruler of all creation, in the name of Thy mighty mercy, through the sign of the Holy Cross and the virginity of Holy Mary, the obedience of Holy Michael and the love and merits of all Thy Saints, I beseech Thee, guide me better than I have deserved of Thee; direct me according to Thy will and the needs of my soul better than I myself am able; strengthen my mind for Thy will and the needs of my soul; make me steadfast against the temptations of the devil; keep foul lust and all evil far from me; shield me from my enemies, seen and unseen; teach me to do Thy holy will, that I may inwardly love Thee above all things with clean thought and chaste body. For Thou art my Maker and my Redeemer, my life, my comfort, my trust and my hope. Praise and glory be to Thee now and forever and unto the endless ages. Amen.
(The use of the word 'merits' probably indicates the influence of Augustine in the thinking of early English Christians. The prayer is Orthodox, though most Orthodox would pray, after 'through the sign'... 'through the intercessions of the Holy Virgin Mary, the Holy Archangel Michael, and all of thy Saints...' then again, Alfred might've known what he was talking about more than me :) - it's an original prayer nonetheless. )