Knight

Knights (アーマーナイト, Armor Knight), also known as Armor Knights or Armors, are heavily armored foot units that usually use lances. They are generally very slow, but have very good defense and attack. They are one of few classes that count as armored units, which leaves them vulnerable to bonus damage from weapons such as Armorslayers and Hammers. They usually promote to Generals. In Fire Emblem: The Sacred Stones, Knights are one of the promotion options of Recruits, and may promote into either Generals or Great Knights. In Fire Emblem Gaiden, they are a second-tier class that can promote to Baron. Armor Knights appear in all games in the series, in addition to Tear Ring Saga and Berwick saga.

Knights are not able to class change in Fire Emblem: Ankoku Ryū to Hikari no Tsurugi, despite the General class already existing at the time.

Combat
Knights are powerful because their defense and HP is usually so high that it can hold off a variety of attackers for a number of turns while dealing out solid damage. Due to this, it is a good idea to put out your Knights to stall a strong character or protect a weak one so they generally work best on the front lines. Movement for Knights tends to be low, so usage of boots is often recommended. The main threat to a knight is the Armorslayer as that can almost take out a Knight and it is not difficult to access due to its fairly low weapon level. Other variants do exist, though, such as the Rapier and Wing Spear. The main weakness of Knights is that they have low Resistance, so Magic attacks can penetrate their defense without a lot of difficulty.

Variations
In Fire Emblem: Genealogy of the Holy War, Thracia 776 and Radiant Dawn, there are a few Knight variations:

Axe Armor
Axe Armors (斧重装兵/アクスアーマー, Heavy-Armored Axe Soldier/Axe Armor) are knights only able to use axes. Dalsin, from Thracia 776, is a playable example. In Radiant Dawn, they would promote to Axe Generals.

Bow Armor
Bow Armors (ボウアーマー, Bow Armor) are only featured in the Jugdral Series games. They can use only bows, and are an enemy-only class.

Lance Armor
Lance Armors (槍重装兵/ランスアーマー, Heavy-Armored Lance Soldier/Lance Armor) are the most common variety of this class, employing Lances as weapons. In most games, they're just called Knights (or Armor Knights, in the Japanese versions). In Radiant Dawn, they're the first-tier class of the Lance Generals.

Sword Armor
Sword Armors (剣重装兵/ソードアーマー, Heavy-Armored Sword Soldier/Sword Armor) are sword-wielding knights. Playable examples are Arden and Meg. In Radiant Dawn, they promote to Sword Generals.

Fire Emblem: Awakening
Lance rank: A
 * HP: 60
 * Str: 30
 * Mag: 20
 * Skl: 26
 * Spd: 23
 * Lck: 30
 * Def: 30
 * Res: 22

Fire Emblem: Ankoku Ryū to Hikari no Tsurugi/Fire Emblem: Shadow Dragon

 * Draug- knight of Altea who accompanies Marth to Talys
 * Dolph- knight of Archanea who is loyal to Nyna
 * Macellan- knight of Archanea who is loyal to Nyna
 * Roger- knight of Grust who falls in love with Sheeda

Fire Emblem Gaiden

 * Valbar - A knight who fights against Dahha
 * Promotion for: Ruka, Fols

Fire Emblem: Genealogy of the Holy War

 * Arden (Sword Armor) - Knight of Chalphy

Fire Emblem: Thracia 776

 * Dalsin (Axe Armor) - Knight of Manster who joins Leif after his brother is rescued
 * Weissman (Sword Armor) - Servant of Raydrik and boss of Chapter 1.

TearRing Saga: Utna Heroes Saga

 * Norton - Leader of Wellt's castle guards and a close friend of Lionel
 * Billford - The "Wild Bull of Barge"

Fire Emblem: Binding Blade

 * Bath - Knight of Ostia
 * Bors - Knight of Ostia and Wendy's older brother
 * Wendy - Knight of Ostia and Bors' younger sister, the first female knight in the series.
 * Rude

Fire Emblem: Rekka no Ken

 * Wallace - Retired knight of Caelin
 * Oswin - Knight of Ostia
 * Wire - Boss of Chapter 11: Another Journey in Hector's story
 * Bauker - Commander of the Imperial Guard of Laus
 * Bool - An assassin sent by Lundgren to kill Lyn in Araphen
 * Yogi
 * Boies

Fire Emblem: The Sacred Stones

 * Gilliam - Knight of Frelia
 * Breguet
 * Saar
 * Promotion for: Amelia

Fire Emblem: Path of Radiance

 * Gatrie - Member of the Greil Mercenaries
 * Brom - A new recruit in the Crimean army
 * Dakova
 * Maijin
 * Karuma

Fire Emblem: Radiant Dawn

 * Meg (Sword Armor) - Brom's daughter
 * Zaitan - Knight of Begnion guarding a Daein storehouse
 * Burton
 * Laverton
 * Djur

Fire Emblem: Awakening

 * Kellam - Knight of Ylisse
 * Kjelle - Sully's daughter from the future.
 * Raimi - Knight of Ferox and boss of Chapter 3.
 * (Spotpass) Valbar, Amelia, Brom, Nephenee, Arden

Fire Emblem: Fates

 * Effie - A strong knight who is one of Elise's retainers.
 * Benoit - A kind-hearted Nohrian knight who likes animals.
 * Ignis - Benoit's Son.

Gallery
Caballero