What were the Targaryens doing before the conquest?

According to cannon the Targaryens got to Dragonstone in 114BC and sat in their hands for the next 114 years. I can’t imagine being one of the most powerful forces in the plaent that they didn’t do anything until Aegon went to war with volantis. Also what made Gaemon so glorious? And why were their so many lords of Dragonstone before the conquest it’s almost a worrying amount. It defiantly implies a lack of stability.