Knights.

Knight:
Knights are the next rank in protection in the kingdom. Knights are chosen by their skills in combat which is shown by hard work, and dedication to the kingdom. They are known to be strong and fearless when in battle and their loyalty to the royal family is never doubted.

Their armor is known to be much tougher than guard armor. The armor is strong and light even for it's appearance. It's also easy to move around in. As for captain armor, it is very detailed and almost impenetrable. Though it might not be as light as regular knight armor it is extremely strong.

Ground Captain:
Cround Captains are in charge of Ground Knights. There are a total of 2 Ground Captains, each in charge of their own fleet of around 25  men/women. Their job is to deal with ground attackers, their fleet has weapons such as firearms (pistols,rifles, etc.). They also use many other weapons, swords, spears, daggers, etc. They are also able to lead their fleet outside of the kingdom to take over land, but must be given the King's permission. (Don't forget that they are able to ride horses into battle)

Captains usually ride on black stallions while his/her fleet uses gray, or brown horses.

Sky Captain:
Sky Captains are in charge of the walls of the kingdom. He/She keeps a watch out in case of attackers and alarm other knights of upcoming conflict. They stay on the wall patrolling day and night. The weapons they use are very little. The captain takes charge of the use of the catapults and ballistas. Their fleet is given cross bows or just regular bow and arrows.

The job is quite boring at times but it is only for extra protection.

Rune Knight:
Rune knight is the highest in knighthood. Only one knight is given this title and their job is to be loyal to the royal family at all times. Like a bodyguard, they are always keeping the royal family safe. The knight is never to leave the King/Queen's side and follows them everywhere. They are looked up to from other knights and have more power than captains do.