In the past many conflicts and acts of violence were predominantly caused by male leaders. Therefore, there is a beliefe that females could make more peaceful governors. Despite causing chaos, i strongly belive that men improved the world to better as well than did women.
Males are naturally more agressive: it is natural for them to be involved in conflicts and cause some acts of violence to appear, and historically, they have started most of wars. However, we should not forget that most of these wars were not solely due to the interests of male emperors. They were started to flourish emperor’s countries and the life of its citizens or to defend it. In any society even governed by a woman there might be an escalations that are unavoidable. Therefore, at some point these conflicts might happen anyway, and the fact that males are governor at that point does not necessarily mean that they are the main cause.
Having said that, not all of female emperors have been negotiators either. According to the historical records, there had been even more brutal women leaders as well. For example, Elizabeth II who led the british army to collonize some of African countries, and the collonization process did in fact involve violence and conflicts. Moreover, a great ancient Greek female emperor Tomaris ,who is notoriously known for her way of killing her enemies, is an another example of feminine brutality. There are also some records of her invading her neighbour countries and commiting genocide of the whole nations.
In conclusion, the gender of leaders does not always play a role in some actions, both male and female governors had good and bad impact on their country during their governing time, so pinpointing a certain action to the gender would not be right.