its superstitions--had reached its
lasting shape.

Gregory the Great had not long passed away when there arose in the East
that new religion which was to shake the world, and to bring East and
West once more into a prolonged conflict. Mohammedanism, born in Arabia,
hurled itself first against Asia, then swept North Africa. By the end of
the seventh century it was threatening the Byzantine Empire on one side
of Europe, and the Gothic dominion in Spain on the other. On the other
hand, in the same period, Latin Christianity had decisively taken
possession of England, driving back that Celtic or Irish Christianity
which had been beforehand with it in making entry to the North.
Similarly, it was the Irish missionaries who began the conversion of the
outer Teutonic barbarians; but the work was carried out by the Saxon
Winfrid (Boniface) of the Latin Church.

The popes, however, during this century between Gregory I. and Gregory
II. again sank into a position of subordination to the imperial power.
Under the second Gregory, the papacy reasserted itself in resistance to
the Emperor Leo the Isaurian, the "Iconoclast," the "Image-breaker," who
strove to impose on Christendom his own zeal against images. To Leo,
images meant image-worship. To his opponents, images were useful
symbols. Rome defied the emperor's attempt to claim spiritual
dictatorship. East and West were rent in twain at the moment when Islam
was assaulting both West and East. Leo rolled back the advancing torrent
before Constantinople, as Charles Martel rolled it back almost
simultaneously in the great battle of Tours; but the Empire and the
West, Byzantium and Rome, never presented a united front to the Moslem.

The Iconoclastic controversy threw Italy against its will into the hands
of the image-worshipping Lombards; and hate of Lombard ascendancy turned
the eyes of Gregory's successors to the Franks, to Charles Martel; to
Pepin, who obtained from Pope Stephen sanction for his seizure of the
Frankish crown, and in return repressed the Lombards; and finally to
Charles the Great, otherwise Charlemagne, who on the last Christmas Day
of the eighth century was crowned (Western) emperor and successor of the
Caesars.

_II.--The Western Empire and Theocracy_

Charlemagne, the first emperor of the restored or Holy Roman Empire, by
his conquests brought into a single dominion practically all Western
Europe from the Elbe and the Danube to the Ebro. He stood the ch