First mentioned in chapter 2305, and further elaborated in chapter 2315.
A Knight Division is a specialized team of NPCs who have been hired by a Lord to protect their territory.
In order to recruit NPCs to join the division, players can commission the Adventurer’s Association to conduct a draft in NPC cities and towns for a cost. A draft in a town would cost 10 Gold per week, 100 Gold per week in a city, 300 Gold per week in a kingdom's capital, and 1,000 Gold per week in an imperial capital. 
After hiring the knights, the Lord has to purchase their equipment as well. A full set of Level 100 to 150 Epic equipment costs 4,000 Gold. A full set of Level 100 to 150 Secret-Silver Equipment costs 50 Gold. 
Salary and Nurturing
After recruiting NPCs into the division, the Lord is responsible for paying them a salary and their equipment. Each knight's salary is dependent on their Growth Potential.
Tier 2 Salaries and Nurturing Fees
To hire and nurture a Bronze ranked, Tier 2 Knight, it would cost 30 Gold as a weekly salary and an additional 20 Gold as a weekly nurturing fee.  Mysterious-Iron Knights request for a weekly salary of 70 Gold and a 30 Gold weekly nurturing fee.  Secret Silver Knights request for a weekly salary of 150 Gold and a 50 Gold weekly nurturing fee.  Fine-Gold Knight request for a weekly salary of 300 Gold and a 100 Gold weekly nurturing fee.
Tier 3 Salaries and Nurturing Fees
For a Bronze ranked Tier 3 Knight, it would cost 200 gold as a weekly salary and an additional 100 Gold as a weekly nurturing fee. 
When the knights reach Level 100, they automatically challenge their Tier 3 Promotion Quest and after succeeding, the Lord has to pay a procedural fee of 10 Gold to the Adventurer Alliance to complete their promotion. 
Bronze ranked Tier 2 Knights have less than 5% chance of completing their Tier 3 Promotion Quest, while Mysterious-Iron ranked Knights would have less than 10% change. Only Secret-Silver ranked Knights have above 80% chance to complete their Tier 3 promotion.