I will be using some military terms and medieval type words that you don't know the meaning of. This and whatever else I decide to put here will be explained. If this book somehow becomes popular I will also be answering some questions on this notice in the future.
definitions:
league: one nautical mile or 3.452 miles
military unit sizes: The smallest unit in an army is the squad, which contains 7 to 14 soldiers and is led by a sergeant. (A slightly larger unit is a section, which consists of 10 to 40 soldiers but is usually used only within headquarters or support organizations.) Three or four squads make up a platoon, which has 20 to 50 soldiers and is commanded by a lieutenant. Two or more platoons make up a company, which has 100 to 250 soldiers and is commanded by a captain or a major. The function of administration is introduced at this level, in the form of a headquarters platoon administered by a sergeant and containing supply, maintenance, or other sections. Two or more companies make up a battalion, which has 400 to 1,200 troops and is commanded by a lieutenant colonel. The battalion is the smallest unit to have a staff of officers (in charge of personnel, operations, intelligence, and logistics) to assist the commander. Several battalions form a brigade, which has 2,000 to 8,000 troops and is commanded by a brigadier general or a colonel. (The term regiment can signify either a battalion or a brigade in different countries' armies.) Two or more brigades, along with various specialized battalions, make up a division, which has 7,000 to 22,000 troops and is commanded by a major general. A division contains all the arms and services needed for the independent conduct of military operations. Two to seven divisions and various support units make up an army corps, or a corps, which has 50,000 to 300,000 troops and is commanded by a lieutenant general. The army corps is the largest regular army formation, though in wartime two or more corps may be combined to form a field army (commanded by a general), and field armies in turn may be combined to form an army group.