Today, we're going to talk about more recent history. It's still okay if you don't have names for your people and groups yet. Tomorrow starts the languages and naming section (yay!) so today, just call them "Group A" or "The Bad Guys" or whatever you need to to keep yourself sane.
By now, you have a geography, a map, and a general sense of groups of people living on the land. Yesterday, you approached some of the questions that might crop up in your novel, but there are also questions that pre-date your novel.
Who lives where, and what wars and conflicts have they had? Who keeps the peace? How do borders stay in place? What happens when power shifts? What major resources are considered necessary to staying in power?
As you answer these questions, you'll find that patterns emerge. A necessary resource is close to the boundary between two cultures. The peace-keeping forces don't always stay in power. Shifts in power result in conflict and war.
A note about war and its effects. In a ground war, crops are destroyed, either by being seized and eaten, or by being burned (to prevent the other side from getting them). A lack of crops means famine, which leads to disease. There is a reason that War, Death, Pestilence, and Famine are the Four Horsemen of the Apocalypse-- they go hand-in-hand whenever conflict gets violent. For those who are also telling a woman's story, war tends to be especially bad for women, as rape is often considered a valid form of warfare. Not only does this kill many women, but it may also leave them with unwanted pregnancies, disease, and of course the psychological effects of PTSD. By "women," let's also not kid ourselves about maturity, shall we-- when a soldier is engaging in rape, he's not really checking to see if she's of legal age. When you write a war into your timeline, remember that wars are never really good, even for the winners; recovering from a war takes about a generation without major conflict.
Spend 15 minutes outlining the major historical events of the last 100 years before your novel begins.
Include in your timeline:
Dates when power shifted in your civilization(s) (through coup, death of a monarch, revolution, election, etc.), and whether the power shift was smooth (as it might be when a monarch dies and their offspring takes their place)
Dates when a natural event reduced or increased the amount of natural resources (food, usually, but also water, timber, and other resources).
Dates when an unnatural event (such as a magical or technological event) changed the resources as well.
Each of these factors (power shifts and resource shifts) puts pressure on the civilizations. At the high-pressure points, write "battle/conflict"-- those are points at which violence may have erupted between cultures (or, if you have non-violent people, perhaps conflict that's expressed in other dramatic ways). Events may also be interrelated-- a technological event might give the edge to one power group, which forces other groups to respond, often with confrontation.
The last dates to write on your timeline: Date your novel begins, and the date your character was born (so you know what part of history he or she directly remembers).
Tuck this timeline into your notebook; you'll need it later! In fact, if you have a politically-oriented storyline, you'll probably need more than 100 years of history and more than one timeline to represent everything that's happening, so spend as much time on this part as you like. There's no need to limit yourself to 15 minutes.