Warlord

The Warlord is a fourth edition class that acts as a battle-Buffer, military officer material. He swings a weapon in fights, but most of the time a Warlord is shouting hitpoints back into his allies giving them extra shift moves ("no no no, you're doing it wrong, you should be standing over HERE and swinging like THAT..."), and performing similar feats of battlefield control.

To quote our good frienemies over at TVTropes:

"A Warlord is a sub-par fighter and a sub-par healer, but grants immense tactical advantages to the rest of the party - bonuses to initiative, extra moves, extra attacks. Great for the strongly teamwork-oriented player, but a poor choice for those who yearn to be The Hero. The saying is: 'A barbarian hits you with his axe; a warlord hits you with his barbarian.'"

Some Warlords lean more on their Charisma, while others rely on Intelligence, but Strength is important to every warlord. (Unless you are a dumb Lazylord, at which point your party should realize that you are just shouting commands to them instead of fighting and feed you to some dire weasels). Warlords also have a bowlord option, which is limited but not terrible

The two builds in PHB 1 are:

INSPIRING WARLORD

The buffing archetype. Your signature powers are Charisma-based, and are meant to help your allies, either by healing, removing debuffs, or defending them.

TACTICAL WARLORD More about debuffing enemies, and moving them around to help your party get more hits in. The latter becomes literally true with the Commander's Strike power, which is the keystone of the "lazylord" build. Most of your non-beatstick abilities draw their power from Intelligence.

The warlord's ideal place is front and centre, stabbing the fuck out of the party's enemies. It's a pretty good melee class, but the Warlord's main goal is to give his allies extra moves, attacks and heals. From a pure combat perspective, warlords are kind of like Paladins, only more versatile, and without the extra boosts against undead.

In fifth edition, it got killed off as its own thing. However, there are options for bringing it back; the Battle Master and Banneret Fighter archetypes both are pretty close to the Warlord's theme, and if you want to preserve the emphasis on healing/buffing, the Bard can actually work out pretty well if you take the College of Valor (or, to a lesser extent, the Unearthed Arcana-provided College of Swords).