It is at once apparent from these directions how utterly the efficiency of the Byzantine infantry differed from that of the legions of an earlier day. The soldiers of the first century, armed with sword and pilum alone, were destroyed from a distance by the Parthian mounted bowmen. The adoption of the bow by infantry had now changed the aspect of affairs, and it was the horse-archer who now found himself at a disadvantage in the exchange of missiles. Nor could he hope to retrieve the day by charging, since the ‘scutati[33],’ or spearmen carrying the large shield, who formed the front rank of a Byzantine ‘tagma,’ could keep at bay horsemen armed, not with the heavy lance of the West, but merely with scimitars and short javelins. Hence the Turk avoided conflicts with the imperial infantry, and used his superior powers of locomotion to keep out of its way. It was only the cavalry which could, as a rule, come up with him. The tactics calculated for success against the Slavs call for little notice. The Servians and the Slovenes possessed hardly any cavalry, and were chiefly formidable to the imperial troops when they kept to the mountains, where their archers and javelin-men, posted in inaccessible positions, could annoy the invader from a distance, or the spearmen could make sudden assaults on the flank of his marching columns. Such attacks could be frustrated by proper vigilance, while, if the Slavs were only surprised while engaged in their plundering expeditions into the plains, they could be ridden down and cut to pieces by the imperial cavalry. To deal with the Saracen[34], on the other hand, the greatest care and skill were required. ‘Of all barbarous nations,’ says Leo[35], ‘they are the best advised and the most prudent in their military operations.’ The commander who has to meet with them will need all his tactical and strategical ability, the troops must be well disciplined and confident, if the ‘barbarous and blaspheming Saracen[36]’ is to be driven back in rout through the ‘Klissuras’ of Taurus.