Medieval pike formations tended to have better success when they operated in an aggressive fashion. The Scots at the Battle of Stirling Bridge (1297), for example, utilized the momentum of their charge to overrun an English army while the Englishmen were crossing a narrow bridge. At the Battle of Laupen (1339), Bernese pikemen overwhelmed the infantry forces of the opposing Habsburg/Burgundian army with a massive charge before wheeling over to strike and rout the Austro-Burgundian horsemen as well. At the same time however such aggressive action required considerable tactical cohesiveness or suitable terrain to protect the vulnerable flanks of the pike formations especially from the attack of mounted man-at-arms, when these features not available Medieval militia pikes often suffered costly failures such as at Battles of Mons-en-Pevele (1304), Cassel (1328), Roosebeke (1382) and Othee (1408). The constant success of the Swiss mercenaries in the later period was attributed to their extreme discipline and tactical unity due to semi-professional nature, allowing a pike block to somewhat alleviate the threat presented by flanking attacks.