Prague is closely connected to the Thirty Years War (1618-48). The conflict started in Prague Castle on 23 May 1618 when tensions between Catholics and Protestants peaked after two Catholic Governors were thrown out of a window by Protestant nobles during a meeting of the Bohemian Estates. Luckily the unfortunate pair landed safely on a pile of manure and survived - thanks, it was piously believed, to the intervention of angels. This may have been the window in the Chancery out of which they were thrown:
The following year the Protestant nobles deposed Ferdinand II as King of Bohemia and elected the Protestant Elector Palatine, Frederick, who was married to James I's daughter, Elizabeth Stuart, and is known as the 'Winter King' due to his short reign. At first, things went well for the Protestant Bohemians, but they were decisively defeated at the Battle of White Mountain (Bílá hora), on the outskirts of Prague, on 8 November 1620.
A decisive factor in the battle was a Spanish Carmelite, the Venerable Dominic á Jesu Maria (who can just be made out in the fresco above), who blessed the Catholic troops with an image of the Adoration of the Shepherds which had been defaced by Protestants and he had rescued from the town of Strakonice. The picture was later taken to Rome and placed in the Carmelite church of Santa Maria della Vittoria (more famous for Bernini's St Teresa in Ectasy). Unfortunately the miraculous image was destroyed, together with the High Altar, in a fire in 1833, though a copy can be seen there today.
Near the battlefield of White Mountain, a pilgrimage church, also dedicated to Our Lady of Victories, was later built and another copy of the picture can be seen above the High Altar.
If you're in Prague, it's well worth making the short excursion to Bílá hora, which is a tram terminus and so quite easy to get to. As well as visiting the pilgrimage church (which we accessed by ringing the bell) and trudging around the field behind, you can visit a star-shaped hunting lodge (Hvězda) in which there is a small exhibition. Here is the Roman Miscellenist at the memorial to the fallen on the White Mountain:
After the battle the Catholic forces entered Prague, the 'Winter King' fled and Ferdinand II was restored. The way was prepared for the triumph of Catholicism in Bohemia - with the help of the Jesuits and other Orders, the towns were evangelized and many of the fine churches that now ornament the Prague skyline were built. According to one school of history, White Mountain was a national calamity, leading to a loss of independence (Bohemia was now firmly wedded to the Holy Roman Empire) and the decline of Czech culture and language. However, I was pleased to see the English leaflet available to visitors argue: 'in terms of cultural orientation and linguisitic knowledge, however, the majority of the Protestant leaders of the Estates were actually German. Conversely, in the following centuries, the Catholic Church deserves the main credit for averting the demise of the Czech language and folk culture and also for promoting the unprecedented development of baroque art in the Bohemian lands.'