Complex sentence: In 1895, a pro-Russian official tried to remove the king of Korea to the Russian legation and failed, but a second attempt succeeded so for a year the King reigned from the Russian legation in Seoul.
Split into simpler sentences: In 1895, a pro-Russian official tried to remove the king of Korea to the Russian legation and failed, but a second attempt succeeded. Thus, for a year, the King reigned from the Russian legation in Seoul.