Louis XVI´s decision to summon the estates-general prove disastrous because during it, the Third Estate , representing the Commoners decided to form a National Assembly, inviting the other two Estates ( Clergy and Nobility) to join them against the King. This is considered to be the start of the French Revolution.
Roma was facing a political crisis, many senators and politicians were fighting to see who gains power of Rome and Octavian the son of Caesar become the sole ruler of Rome and saved everyone from more bloodshed. (from the civil war)
Theodosius was the last emperor to rule over both the eastern and the western halves of the Roman Empire. ... He also issued decrees that effectively made Orthodox Nicene Christianity the official state church of the Roman Empire
Because they reflect historians points of view most important events. Hope this helped <3
