Well, it is difficult to offer an objective measure of deaths from organised violence, since accurate records only stretch back so far, and the various peaks and trends will vary depending on where you draw the baseline from.
One also has to take into account the relative proportions of deaths to total populations ; For instance, in the english civil war, absolute number of deaths was smalerl in comparison to, say, the number of english deaths recorded in WW2, but were far higher in proportionate terms, because of the relative population sizes. So which was the bloodier, more violent war in that circumstance?
And it is probably not a fair comparison to contrast between modern civilisation and ancient civilisation and human society in prehistoric terms.
Modern day civilisation has only been around for an eyeblink, in evolutionary terms, but you can already see massive differences in the recognition of the cost and quality of life, at least in my opinion.
The bloodiest continent in the world, globally speaking, is europe -but since the last outbreak of madness in WW2, europe has been relatively calm, although there have been outbreaks of ethnic cleansing and other such organised violence around the edges.
Development of law and order, international law, trade treaties, economic co-operation all point to a maturing civilisation which recognises that we need to co-operate rather than dominate. Something like the ECHR, often derided on AB, is yet another example of the civilisational impulse.