General

Generals are the promoted versions of Knights. They have excellent defense, good attack, surprising evasive ability for their size and low resistance. They are quite slow, but what they lack in maneuverability they make up for with defensive and offensive ability. Many of the bosses in several games are generals (or their lesser form earlier in the game)

Combat
Generals can be used like "walls" to block enemy forces and are quite useful in survival and defense objective battles. They can be used to block small entrances to prevent opposing units from getting past them, this is very useful if you wish to stop thieves from escaping. A General's weaknesses are magic and anti-armor weapons, as well as fast moving durable and powerful characters like Heroes, experienced Paladins and Warriors. In many newer games such as Radiant Dawn and Awakening, Generals have higher magic stats, thus making speedy units and anti armor weapons their prime weakness.

The rarity of a general ever being out matched on the field through sheer brute force is high, which means they are very valuable to any team and their durability is very helpful to weaker units as they can hide behind them. Another thing that helps Generals is that in some games they gain the ability to use bows which can deal with Mages slightly but you should not risk using a bow to completely destroy one (Unless you are using something like a Killer Bow or Parthia, neither of which are very likely due to their high weapon level)

In Radiant Dawn, Generals can Promote to Marshall, greatly improving most stats.

In WiFi battle, Generals suffer greatly for their low speed cap. Although their high defense means they can survive even four hits from a swordmaster, they cannot survive being doubled by a Berserker or Sage. They lack high movement, and are affected by weapons like Armorslayers. Individually, these flaws can be addressed by cards, but combined they cannot. Generals have high attack, and can use bows. Using a General often means leaving the fate of a battle in the opponent's choice of squad. If a General is placed up against a Swordmaster, and the Swordmaster does not have an Armorslayer, the battle can be quite even (especially using cards like Fleet Feet). However, due to the relative ease of counter-picking teams to beat Generals, it is difficult to use them reliably on WiFi.

Weapon Usage
Generals have been in every Fire Emblem game to date, (Except Gaiden, where they were renamed to Barons) and have had varying weapons available for them. This chart shows the differences.

Genealogy of the Holy War

 * HP: 80
 * Str: 25
 * Mag: 15
 * Skl: 21
 * Spd: 20
 * Luck: 30
 * Def: 27
 * Res: 18

Path of Radiance

 * HP: 60
 * Str: 29
 * Mag: 20
 * Skl: 27
 * Spd: 24
 * Lck: 40
 * Def: 30
 * Res: 25

Radiant Dawn (as Lance General)

 * HP: 45
 * Str: 27
 * Mag: 15
 * Skl: 25
 * Spd: 23
 * Lck: 30
 * Def: 30
 * Res: 30

Shadow Dragon

 * HP: 60
 * Str: 27
 * Mag: 20
 * Skl: 25
 * Spd: 21
 * Lck: 30
 * Def: 30
 * Res: 20
 * Lance: A, Bow: A

Fire Emblem : Awakening

 * HP: 80
 * Str: 50
 * Mag: 30
 * Skl: 41
 * Spd: 35
 * Lck: 45
 * Def: 50
 * Res: 35
 * Lance: A, Axe: A

Skills
In Fire Emblem: Genealogy of the Holy War, Fire Emblem: Thracia 776, and Fire Emblem: The Sacred Stones, Generals have the skill Great Shield.

In Fire Emblem: Path of Radiance, generals can learn Luna as their Occult skill, while in Radiant Dawn they learn it automatically when they promote to Marshalls.

Ankoku Ryū to Hikari no Tsurugi/Shadow Dragon

 * Lorenz - A general of Grust who opposed his country's alliance with Dolhr, and an old friend of King Mostyn of Talys
 * Horace - A general of Akaneia who was forced to betray his country to protect his people
 * Emereus
 * Harmein
 * Zharov
 * Hollstadt
 * Jiol - The king of Gra who betrayed Altea and sided with Doluna
 * Dactyl
 * Larissa

Possible promotion for: Draug, Macellan, Dolph, and Roger (such promotions are only possible in Shadow Dragon)

Mystery of the Emblem

 * Sheema - Daughter of King Jiol and later the ruler of Gra
 * Lang - General of Akaneia and leader of the Grust Occupational Army
 * Possible promotion for: Draug

Genealogy of the Holy War

 * Hannibal - A general of Thracia who is known as "The Shield of Thracia" and the foster father of Corpul

Possible promotion for: Arden

Thracia 776

 * Xavier - Former general of Leonster who sided with Freege in order to protect Leonster's people
 * Possible promotion for: Dalsin

Binding Blade

 * Douglas - The Great General of Etruria
 * Hector - The Marquess of Ostia, Lilina's father, and one of the main characters of Fire Emblem: Rekka no Ken
 * Murdock - The military commander of Bern and the leader of the Three Dragon Generals
 * Roartz - Noble of Etruria who betrayed his country and sided with Bern

Possible promotion for: Bors, Wendy, and Bath

Rekka no Ken

 * Darin - The Marquess of Laus
 * Murdock
 * Lundgren - The younger brother of the Marquess Hausen of Caelin who attempted to overthrow his brother
 * Uther - The Marquess of Ostia and Hector's older brother

Possible promotion for: Wallace, Oswin

The Sacred Stones

 * Vigarde - The "Silent Emperor" of Grado
 * Tirado
 * Fado - The king of Renais

Possible promotion for: Gilliam and Amelia

Path of Radiance

 * Tauroneo - A general of Daein and a former member of the Four Riders of Daein
 * Bryce - One of the Four Riders of Daein
 * Black Knight - One of the Four Riders of Daein

Possible promotion for: Gatrie and Brom

Radiant Dawn

 * Tauroneo
 * Brom
 * Gatrie - Member of the Greil Mercenaries

Possible promotion for: Meg

Shin Monshō no Nazo

 * Macellan - Knight of Akaneia loyal to Nyna
 * Dolph - Knight of Akaneia loyal to Nyna

Awakening

 * Ignatius - A Valmese commander and boss of Chapter 14.
 * Cervantes - One of Walhart's officers and boss of Chapter 16 and 20.
 * Mus - Enemy from Chapter 22 and one of the Deadlords. Boss of Infinite Regalia.
 * Possible promotion for: Kellam and Kjelle

Trivia

 * In Awakening, the General class can be seen as a parallel to the Wyvern Lord: both have the highest Strength & Defense caps (on the ground and in the air respectively), both have a status which makes them vulnerable to a certain type of weapon (in the case of the General, being weak against Armorslayers, Hammers, and Rapiers/Noble Rapiers) and both classes wields Axes and Lances.
 * The General's Defense cap is the highest of all playable classes and is tied with the Berserker class for the highest Strength cap in Awakening.
 * Generals possesses the lowest Speed cap of all promoted classes in Awakening.