After Tamerlane: The Rise and Fall of Global Empires, 1400-2000 is John Darwin's account of how a somewhat backward fringe of Eurasian civilization came to dominate the world with global empires and how those empires collapsed. This is big picture history. Those colorful characters who do so much to give human scale and character to history are hardly present, because Darwin is far more interested in global features. It's a major loss, from my point of view.
On the positive side, his mile high view of history makes clear a lot of trends and large scale phenomena that might remain obscured in a finer grained (and more human) history. I was especially interested in two central themes - the notion that European predominance was essentially accidental and the degree to which events, once underway, have their own momentum, beyond the control of any of the actors.
Europe in the Fifteenth Century knew that it was on the outskirts of civilization, and so did the rest of the world, to the extent that it knew of Europe at all. Almost certainly it was not the only part of Eurasian civilization which had the capability to cross the seas and find the New World. Unquestionably China did, and almost certainly the Indian and Arab traders who worked across the Indian Ocean did as well. What the latter lacked was motivation and inclination. Portugal and Spain wanted to get to the Orient. The Orient could hardly have cared less about them.
The purely accidental discovery of the New World, and the naval capabilities developed in getting there and around Africa were critical components in the development of the military power that created empire. Perhaps equally important was the way that these discoveries shattered old world views and opened the European mind.
It's plausible to guess without the fall of the Indian domino, the story would have been very different. Again, India fell into British hands almost by accident. The unlucky combination of external invasion from Central Asia, a crumbling Mughal Empire, and the internal struggle to pick up that empire's pieces made it peculiarly vulnerable. Add in a tax system capable of being co-opted and local interests willing to cooperate, and the conquest of India became self-financing. The loot from the Indian treasure house became the foundation of the greater British empire.
The end of the European empires was more sudden. The great cataclysms of the Twentieth Century struggles among the Europeans weakened them militarily, economically and morally. Meanwhile, anti-colonial resistance had been maturing, especially in India. World War II forced Britain to make a deal to free India after the the end of the war, and after that the end seemed inevitable, even if the colonial system managed to stumble on for another generation or so - at least partly because the Soviet threat induced the mostly anti-colonial US to support Britain and France for a few more decades.
My other notes on the book can be found here.