be able to hold out at least temporarily against the barrage. A case in point is Procopius's accounts of Belisarius's wars against the Sassanids where he states how the Byzantine cavalry engaged in massed archery duels against their Persian counterparts. The Persians loosed their arrows with far greater frequency, but as their bows were much weaker, they did not do much damage compared to the stronger Roman bows. The great weakness of mounted archers was their need of space and their light equipment (compared to contemporary heavy cavalry). If they were forced to fight in close combat against better armoured enemies, they usually lost. Furthermore, they were not suited for participating in sieges. For example, although victorious in the field the Mongols originally had been unable to take the fortified Chinese cities until they managed to capture and enlist the services of Islamic siege engineers. The Mongols subsequently failed to retake Hungary in 1280 after the Hungarians became more focused on Western European heavy cavalry and castle building. Good cavalry troops needed much training and very good horses. Many peoples who engaged in this form of classical cavalry, such as the Hungarians and Mongols, practically lived on horseback. The Battle of Dorylaeum (1097) during the First Crusade shows the advantages and disadvantages of mounted archers; the rider groups of the Seljuk sultan, Kilij Arslan I, were able to surround an army of Crusaders and shoot them from a distance. Suddenly, reinforcements under the command of Godfrey of Bouillon arrived, and the Seljuks themselves were encircled. They could no longer escape and were annihilated in close combat. The defeat of the Seljuks at Dorylaeum was so complete that the Crusaders then crossed Anatolia virtually unchallenged. Tactics of heavy cavalry using lances Medieval European knights attacked in several different ways, implementing shock tactics if possible, but always in formations of several knights, not individually. For defense and mêlée a formation of horsemen was as tight as possible next to each other in a line. This prevented their enemy from charging, and also from surrounding them individually. The most devastating charging method was to ride in a looser formation fast into attack. This attack was often protected by simultaneous or shortly preceding ranged attacks of archers or crossbowmen. The attack began from a distance of about 350 metres and took about 15–20 seconds to cross the contemporary long range weapon's effective distance. A