For example, someone takes a close look at a specific battle, explains the short history of the combatants, the equipment used, the terrain and other details.
Also, explanations from the commanders' POV, what they did and why.
I know information like this can be found on wikipedia, I want more in-depth stuff where I can understand easier what the people where thinking at the time. Would be nice to see more battles, where I can see how tactics evolved over time
Any tips?
Have you checked out Julius Caesar's de bello gallico? It's his personal account - written in the 3rd person - of the wars in Gaul. Although there is some debate as to how accurate it is, it's still a very interesting book for qhat you are looking for.