"In the rolling landscapes of Britain and Ireland, minor chiefdoms grew into formidable kingdoms ruling their surroundings from powerful strongholds. Dominate the highlands with swift infantry, terrorize opponents with swarms of Woad Raiders, and unleash the Furor Celtica upon your enemies with durable, fast-firing siege engines. Your legacy will mix history and legend for centuries to come!"
Historically, the Celts were a Central European civilization who dominated much of Europe, such as Southern Germany, Spain, France, Great Britain, and Ireland. The Celts in the game are based on the Celts of Scotland and Ireland, and speak Middle Irish (Gaeilge), the ancestor of Modern Irish and Scots Gaelic. Their unique unit is the Woad Raider, a type of infantry who covers himself in paint made from the woad plant to make himself look more fearsome. Woad Raiders move very fast, allowing them to overcome the normal infantry weaknesses against archers and siege weapons. Their Imperial Age unique technology is Furor Celtica, which refers to the Celtic warrior tradition of channeling their emotions and anger and makes their siege weapons harder to kill. Being masters of guerilla warfare, Celtic infantry move faster. Because of their historical wood and metalworking, their Siege Workshops build faster, their Lumberjacks work faster, and their siege weapons fire faster. Like their neighbors the Britons, the Celts were historically skilled shepherds, and it is much easier for them to steal their enemies' Sheep.
Their descendants are the Scottish and Irish nations. Wales is also considered a Celtic nation, but is not represented by the Celtic civilization. These three nations came under control of the English nation (descendants of the Britons), which created a united kingdom: the British civilization that is featured in Age of Empires III.
The Celts have very good infantry units with a major advantage in their faster movement speed. The other two main branches, archers and cavalry, are very underwhelming, missing key technologies all over the board. Their use in later stages of the game is usually only considered in special circumstances. Their navy is weak as they lack Fast Fire Ships and Bracer which puts their Galleons at a disadvantage. Their Monks are among the weakest of all, missing five of ten technologies. The defenses are average with two missing upgrades (Bracer and Architecture), but their Castle Age unique technology Stronghold helps slightly. They have arguably the best economy of all civilizations in early to mid game. However, their late game economy is slightly below average due to missing Crop Rotation. Their civilization bonus of efficient lumberjacks (+15%) is better than Two-man Saw (+10%, expensive). Their Siege Workshop is the best of all civilizations. The Celts' siege weapons attack quicker (also affects Trebuchets), are built faster, and are more tanky due to Furor Celtica, making them extremely dangerous. They have the worst Blacksmiths (aside from civilizations lacking cavalry, which naturally lack Cavalry Armor technologies), as they lack three technologies, including the important Bracer.
All in all, the Celts have a very lacking technology tree, but if they play to their strengths, their army of infantry and siege weapons can easily be enough to defeat any army. Also, their strong economy helps them in playing outside their strengths in the Castle Age.
When playing a random map game against the computer, the player may encounter any of the following Celt AI characters:
Aedan: Áedán mac Gabráin, King of Dál Riata (West-Scotland) from 574-609. Held campaigns in Ireland, Scotland and to the Orkney islands, but finally decisively defeated by Aethelfrith.
Aethelfrith: King of Bernicia (East-Scotland) from 593-616. Notable for his successes against the Britons and the Gaels (Aedan), laying the foundation for the future kingdom of Northumbria. Killed in battle.
Ainmire: Ainmuire mac Sétnai, High King of Ireland from 566-569. First king from northern Ireland, but soon killed by a rival prince.
Ambrosius: Romano-British war leader from 479 and onwards, victorious in important battles against the Anglo-Saxons in the 5th century. Could, historically, have been the inspiration of, or have influenced, the King Arthur epic.
Athelred the Unready (966-1016): King of the English from 978-1016. Had to defend England against Danish Vikings (Sweyn Forkbeard) but failed and fled to Normandy in 1013. Died in a campaign to retake England (1016).
Brian Boru (941-1014): High King of Ireland (1002-1014). Fought many battles to unify Ireland under him. His Irish won the final battle against the Norse Vikings of Dublin, but Brian died in battle.
Brude: Bridei I, king of the Picts in Scotland from 554-584.
Columba (521-597): Irish abbot and missionary who spread Christianity throughout Ireland and Scotland. His work would be the basis of Celtic Christianity. Today revered as an Irish Saint.
Conall: Conall Cearnach, a hero in Irish mythology and sagas. His epic led him through Ireland, England and mainland Europe, completing various quests along the way.
Cunedda: Celtic leader, originating from northern England, lived around the beginning of the 5th century. Waged war on the Picts and Irish, and later drove them from Wales where he laid the foundation for the kingdom of Gwynedd.
Diarmait: High King of Ireland from 560-565.
Kenneth MacAlpin:was a king of the Picts who, according to national myth, was the first king of Scots.
Macbeth (1005-1057): King of Scotland (1040-1057). Defended Scotland from English attacks, died in battle by a rival. Became a legend in Shakespeare’s tragedy Macbeth.
Maelgwn: Maelgwn Gwynedd, king of Gwynedd (northern Wales) in the beginning of the 6th century. Supporter of Christianity, died from the Plague and passed into Welsh legend.
Robert the Bruce (1274-1329): King of Scotland from 1306-1329. Famous warrior who led the Scots in the First Scottish Independence War, resulting in an independent Scotland.
Rhydderch Hael '('580 –614): was a ruler of Alt Clut, a Brittonic kingdom in the Hen Ogledd or "Old North" of Britain. He was one of the most famous kings in the Hen Ogledd, and appears frequently in later medieval works in Welsh and Latin.
Vortigern: Supposedly King of the Britons, 5th century warlord who fought against the Picts and the Scots.
William Wallace (1270-1305): One of the main leaders of the First Scottish Independence War. Famous for his victory in the Battle of Stirling Bridge (1297). Defeated at the Battle of Falkirk (1298), after which Robert the Bruce took over command of the Scots. William was eventually captured by the English and executed.
"The Celts (pronounced "kelts") were the ancient inhabitants of Northern Europe and the builders of Stonehenge 5000 years ago. Julius Caesar had battled them during his conquest of Gaul. The Romans eventually took most of Britain and the Iberian Peninsula from them as well. At the end of the ancient Roman Empire, the Celts occupied only parts of northwestern France, Ireland, Wales, and parts of Scotland. During the course of the Middle Ages, they strengthened their hold on Scotland and made several attempts to take more of England.
The Irish remained in small bands during the early Middle Ages. By 800 the four provinces of Leinster, Munster, Connaught, and Ulster had risen to power under "high kings." Viking raids began in 795 and then Viking settlements were established in the middle ninth century. The most important of these was at Dublin. Brian Boru became the first high king of all Ireland around 1000. In 1014 the Irish defeated the Danes of Dublin at Clontarf, although Brian Boru was killed.
An Irish tribe called the Scotti invaded what is now southern Scotland during the early Middle Ages, settling permanently and giving the land its name. They pushed back and absorbed the native Picts who had harassed the Romans to the south. The Scottish kingdom took its present shape during the eleventh century but attracted English interference. The Scots responded with the "auld (old) alliance" with France, which became the foundation of their diplomacy for centuries to come. Edward I of England (Longshanks, or "hammer of the Scots") annexed Scotland in 1296.
William Wallace (Braveheart) led a revolt of Scotland, winning virtual independence at the Battle of Stirling Bridge in 1297. Defeated the next year at Falkirk, Wallace waged a guerrilla war until he was betrayed, captured, and executed in 1305. Robert the Bruce declared himself king of Scotland after murdering his main rival. He drove out the English, winning the battle of Bannockburn in 1314. Edward III of England recognized Scotland’s independence in 1328, but war between the Scots and English carried on for several centuries. The crowns of the two countries were united in 1603, long after the Middle Ages were over.
No prince in Wales proved strong enough to unite the country. In the late thirteenth century, Edward I took over the government of Gwynedd, one of the strongest Welsh principalities in Wales. He proceeded to build five great castles in Wales, effectively placing the country under English rule."
Two Celts' AI players are Anglo-Saxon kings. Even though Bernicia and Wessex comprised both Anglo-Saxon settlers and Celtic natives, the natives likely spoke Brittonic languages (like Old Welsh), related to yet distinct from the Goidelic Middle Irish spoken by the in-game Celts. Moreover, the in-game Britons already comprise Anglo-Saxons, Normans, and Brittonic Celts.
The Celts' civilization icon is based on a celtic triskelion.