The study analyzes the entire historiographical research of the mighty parrish church of St. Martin and Mary and the former monumental minorite monastery of 13. century in the austrian county town Hainburg upon Danube and specially the art historical and later also archaeological surveys of their Romanesque and early gothic remains from the time of awaking of the interest of the professional community and subsequently of the regional history in the then heart of the Austrian monarchy after the middle of 19. century until to the decline and ruin of the local awareness and monumental preservation of the medieval heritage in Hainburg in the consequence of disintegration in middle Europe after the second world war.