Originally Posted by Guaporense
Least interesting? Well, in the History of Western Eurasia:
1 - Late Roman period, from 200 AD to 400 AD, things got a bit boring: Rome stopped to expand, starts to vegetate while Ancient civilization stops developing and also begins to vegetate and decline. Numerous inconclusive wars with the Sassanians and with the tribes to the North.
2 - Early medieval period: too few sources and also lack of very interesting social processes of change: society is rather vegetative.
3 - The Medieval Period as whole lacks novelty. There were big Eurasian Empires: the Ancients also had that. They had some proto science: The ancients also had that. For instance, while in the middle ages there were the Arab Caliphate and the Byzantines the Ancients got the Achaemenid Persians and the Roman Empire at it's full glory. On the whole medieval warfare was less advanced than earlier warfare: the clearest example is military force projection and Rome could project power more easily than any medieval state.
It was with the Modern Period that things started to get more dynamic and interesting: the unification of all civilizations into a single global civilization, the creation of massive colonial empires and massive processes of social and political change. The power projection capabilites of Rome were surpassed and continued to progress at exponential rates.
There were more mathematical and scientific advances during the Middle Ages than during the ancient era. Either the development of or the the foundations for Nonastronomical trigonometry, hyperbolic geometry, elliptical geometry, the modern numeral system, the graph, the concept of zero, modern arithmetic, algebraic geometry, the calculation of probabilities (i.e. statistics), the ability to mathematically distinguish between speed and acceleration, uniform and nonuniform acceleration, the "intension and remission of forms" (i.e. how things go from hot to cold), the relativity of motion, and on and on. All of these things formed the basis of modern science.
Also, the basis for parlimentarism, our modern system of government, formed during this period, as did double entry bookkeeping, essential for modern banking and finance. Gothic architecture is very sophisticated. The notion that the Middle Ages was "vegetative" and lacked novelty has been outdated for decades.
Personally, I find every era of history fascinating. But then I'm just an omnivorous glutton for knowledge.