Croatia has gained independence only recently, nevertheless during Middle ages it was independent state and even after losing independence, it retained certain degree of autonomy up to the First world war. This means that through the most of its history Croatian nobility existed and Croatian soldiers had chance to fight for its homeland, not merely for the foreign ruler.
The worst period of Croatian history was 300 years of Ottoman continuous assaults from 15th to 18th century. Croatia was actually Christian borderland, the last Christian area never to be completely conquered by Ottomans, so Croatia was proclaimed as “Antemurale Christianitatis” (“Bulwark of Christianity”). There were many famous battles that Croats fought against Ottomans in that period, alone or with help of the Christian allies, and one of the most famous was Siege of Szigetvar.
The shortened story goes like this: In 1566 Ottoman sultan Suleiman the Magnificent started a campaign toward Vienna with one of the largest armies he had ever commanded. After conquering Belgrade, he came across the fortress of Szigetvar, which was manned by 100 times smaller Croatian garrison under the leadership of Croatian commander Nikola Šubić Zrinski. His forces had no chance, but he still decided to fight as long as possible and wait for a possible help. After one month of siege, and without any help, the situation was hopeless. Instead of surrender, Nikola Šubić Zrinski decided to set the fortress on fire and make a suicidal surprise charge toward the Ottomans, intending to slain as many Ottomans as possible before certain death. And so the legend was born. During the siege Ottoman sultan died, and campaign was abandoned, so tiny Croatian garrison changed the course of history.
Croatian composer Ivan Zajc wrote an opera about this event, which bares name of Nikola Šubić Zrinski. Opera is still very popular in Croatia, especially its patriotic finale, in which soldiers charge toward the Ottomans. The song is called “U boj, u boj” (“To battle, to battle”), which are also the words that are repeating mostly throughout the song.
Song “U boj, u boj” (YouTube)
But this is not the end of the story. After the First world war, few Croatian sailors were stranded in Japanese harbour of Kobe. Japanese hosts liked one of the songs that they performed, probably not only for the tune but for its meaning, so they learned it from the sailors. During the following decades “U boj, u boj” became one of the most popular Japanese songs, and even hymn of a prestigious Japan university. Therefore, many records of Japanese performance can be found on YouTube. In original Croatian language!!!
Japanese singing “U boj, u boj” (YouTube)
Interestingly, after a while the origin of the song was forgotten in Japan. Only in 1970s did a Japanese musicologist realised that the source of the song is Croatia (then part of Yugoslavia). And interesting personal twist for the end: In early 1990s, I was studying in Zagreb, Croatia, and also sung in the academic choir. As a webmaster of the choir web page, I was contacted by one Japanese choir, that wanted help on pronunciation and meaning of the song. Of course I knew the song – we were performing it for our own pleasure after every concert.
End for the end, there is even a Polish version of this song:
Marko Pinteric, Maidan Monitoring Information Center, Slovenia