But Hadji Ilbeki did better than keep the crusaders from crossing the river. They had already crossed, and had celebrated the unopposed passage of the Maritza by an evening of feasting. Hadji Ilbeki surprised them as they were sleeping in a drunken stupor.[272] Without hesitation he fell upon them like a Gideon. Seized with panic, the crusaders were driven back into the river. Those who escaped massacre and drowning fled precipitately. There was no attempt to rally. In the little town of Mariazell, on the northern frontier of Styria near the foot of the Semmering Alps, there stands a votive church built by Louis out of gratitude to the Virgin for having saved him from death in this battle.[273] Lalashahin, instead of rewarding the daring of his lieutenant, which had saved the Osmanlis from an irreparable disaster, was consumed with jealous fury. His only thought when he received the news was that Hadji Ilbeki had robbed him of the glory of so great a victory. He had his too successful subordinate poisoned.[274] The sudden and complete collapse of the first crusade organized against the Osmanlis did not give to Murad any false sense of security. He saw in the successful meeting of this danger, which had threatened to destroy him, not the opportunity for exultation and for the relaxation of effort, but the spur for straining still further every nerve to learn and profit by the lesson. The battle of the Maritza was a warning to Murad. The danger would be renewed, and renewed soon. It was now for him to make the choice between remaining an Asiatic emir and becoming a European sovereign, between endeavouring to impose first his authority on the other emirs of Asia Minor and the conquest of the Balkan peninsula. Were the Osmanlis to be on the offensive in Europe or in Asia? Murad decided to build his empire in the Balkan peninsula. It was not that he coveted less the mountains and valleys of Asia Minor. It was not that his ambitions failed to extend to the Taurus. But he had the vision to realize that the Ottoman race could not subjugate the Turkish elements in Asia Minor by a gradual assimilation of those elements alone. The race had to grow, as it began, by the incorporation of the various Christian elements, which alone possessed the finesse, the knowledge of government, the organizing capacity necessary to cope with the problems of facing Europe and inheriting the Byzantine Empire. From Europe, Asia Minor and more could be conquered: from Asia, no portion of Europe could be conquered.