And really, that's just Earth/Federation history.
We've never seen the Klingons conquered by the Hur'q, or the Hur'q overthrow, we've had only glimpses of pre-united Bajor, we have one line of onscreen dialogue referencing the founding of the Dominion (the pre-Vorta rescued the Founders, so the Founders rewarded them by making them the Dominion's managers), we haven't actually seen any of the Hebitian Age (unless you count the Oralian Way, who are more a Hebitian relic than a living society), we know little about the Vulcan/Andor war, and nothing about the Tellarites. . .
We've never seen the Klingons conquered by the Hur'q, or the Hur'q overthrow, we've had only glimpses of pre-united Bajor, we have one line of onscreen dialogue referencing the founding of the Dominion (the pre-Vorta rescued the Founders, so the Founders rewarded them by making them the Dominion's managers), we haven't actually seen any of the Hebitian Age (unless you count the Oralian Way, who are more a Hebitian relic than a living society), we know little about the Vulcan/Andor war, and nothing about the Tellarites. . .