I know its late. Sorry.
In the near future, the crops, worldwide began to fail. It happened so fast, it was hard to say exactly where the blight began. Some thought it to be Europe, but the blight problem spread. Attempts to contain it failed.
Sources of the blight included terrorism, though no group would take credit, or pollution- a likely culprit. One of the most widely touted was failure of genetic manipulation, a complete breakdown of the crop which affected the soil.
A darker, more fanciful theory, was magic. That somehow the laws of the universe itself were changing, realigning, forcing certain artificial creations to fail. This is the closest to the truth. Soil that, without chemical fertilisers, would be dead, died. Crops failed. The few remaining food sources pushed the cost of basic sustenance well beyond the reach of all but the most privileged.
Civil wars flourished, people rose and took up arms. This, coupled with the rising price of oil, crashed the world economy. People formed gangs in an attempt to take as much of the remaining food stores as possible. Life became cheap.
The situation began to stabilise three years after the failure. Certain technological research facilities forced a breakthrough in the development food production. Algae and lichen were modified, and the research was stolen, for the betterment of the situation.
In northern Alberta, there was reliable sources of meat, and critically, oil. Foreseeing a return to some sort of stability, either through the hard way (massive population reduction through famine, disease, and regionally, cold) or through alternative development. A man developed a plan even as the world crumbled about him.
In the early days of the crisis, he procured weapons, a significant cache, and moved to take the production facilities at Fort McMurray- the major production centre of the oilsands. Even as the Government collapsed, he was moving, and before lawlessness could completely dominate the mines, his men and his guns ensured continued production. In return for safety, and food, the engineers modified a portion of the processing facilities for onsite refining. Using spare metal, he armoured the heavier cars, and had explosive weapons installed. He built an army. Infantry. Armoured cars. And like a winter storm, rode out of the North and into the gang torn streets of the provincial capital.
His resources and knowledge allowed him to dominate the streets of the city in very short time. And to the civilians, he brought food, peace, and warmth. They flocked to him. Small scale cottage factories constructed everything from weapons to basic computer parts. The more advanced technology was scavenged.
From the city, to the province. The storm moved south. Mary Blacke, was the strongest gang leader in Calgary. He entered quiet negotiations with her, she became a general, and a baroness- becoming the first of his nobility. And so, to, the other cities. The warlord, Takashi of Vancouver was made Daimyo, equivalent to Baron. The feudal structure of his government began to take shape. From province to the region. But this did take time, and others did similar things. His empire would stretch from Vancouver to Duck Mountain, from Helena to Tuktoyaktuk.
Borrowing from History, he created the NWMP (North West Militia Police), the military force that represented the His Law. The nobility, too had their own local troops, but command in invasion would go to NWMP officers. Most of the Generals in the NWMP were nobility.
A side effect of the armoured up cars became known as the lists. Sometimes referred to as autojousting. This sport would see armoured and armed vehicles face each other for the entertainment of the crowds. It is an often fatal sport.
But tales of magic, and of spirits grew. Relics could heal, or beget abilities to people. He took the stories seriously, and a special branch of the NWMP was born. The retrievers. These people have the task of obtaining the items. It is a branch of the Militia only known to senior members.
And so, there you have a brief history of the Empire. Mark of Death is set during the Empire's creation. Old Medicine is set well after continental stability had been reset.