danube holiday markets (2025) budapest to passau | 8 days budapest has celebrated christmas for a thousand years, since the reign of st. stephen, the king who founded hungary and encouraged the spread of christianity throughout his realm. as you ramble... ships: river princess, s.s. maria theresa countries: austria, germany, hungary, slovakia river: danube 4.6/5 (140 reviews) from $3,999 per person view itinerary dates & pricing