sentence1: After rival Fujiwara factions had been struggling for years to gain control of the imperial throne, they turned to the Taira and Minamoto armies in 1156 to wage the four-year war that heralded the end of the golden age of the Heian court.
sentence2: After rival Fujiwara faction had struggled for years to gain power, they finally decided to make peace with their opponents, sending Japan into a Golden Age.