Hungary's fiery Prime Minister Viktor Orban has always relished a fight, be it with foreign bankers, international lenders or the European Union over policy toward Russia.

But he now faces the biggest and most bruising battle of his career: trying to manage a migration crisis that has already tarnished Hungary's image and strained ties with Western Europe, especially its most important economic partner, Germany.

Tens of thousands of migrants, many of them refugees from Syria's civil war, have been pouring into Hungary, an eastern outpost of Europe's passport-free Schengen Area, seeing it as a springboard to wealthier Western Europe — above all Germany.