Apparently, the Celts were all over the place, and left an impact everywhere - Greece, Massilia (Maraseilles), Galatia (Turkey), Rome, the headwaters of the Danube, Gaul and Spain.  The mother Goddess of the Celts was "Danu" (water from heaven), from which the Danube received its name.

They were respected for their highly advanced weoponry and tools, and were considered to be militarily superior to most of their neighbors.  About 474 BC they defeated the Etruscans near the Ticino and were in total control of the plains of northern Italy.  When the Romans came to the aid of the Etruscans, the Celts defeated them too.  The Romans were forced to pay a large ransom to get the Celts to withdraw.

The Romans began to adept Celts weapons and even the Celtic words for them into Latin.  The Celts were known for their road-building ability, sophistication in art, pottery making, jewelry making, enamelwork, and advanced metal work. The British Celts were renowned in the Roman world for its woolen trade, and for a Roman to own a British woolen cloak was regarded with much prestige.

The book describes the importance of oak trees (dair) to the Druids, in fact, the acorn was as important as the potato to the Celts.  They ground and baked the acorns into bread, and relied heavily on acorns for food.

The Celts were fastidious in personal appearance.  Soap (sopa) was a Celtic innovation and word.  The books talks about the Celts' road building skills helping them to move around, including the move to Ireland at the start of the first Millenium BC.

The book details the status of women in Celtic society, compared to the Greeks and Romans.  In Greece, women had no political rights at all.  They could take no part in the running of society.  Their social rights were severely limited.  They could not inherit or hold property, or enter into any transaction which involved more than the value of a bushel of grain.  The woman's husband, father or male guardian took complete charge of her affairs.  If her father died without male issue, the daughter "went with the property" to the next of male kin who would accept her as a wife.  Greek women were kept in seclusion in the home.

In Rome, women were generally allowed more rights, but the male still had complete control over his wife, and it was necessary for women to have a male guardian to conduct afairs of business.  Married women in Rome did not live in seclusion but took their meals with their husbands and were free to leave the house, as long as they wore some veil or something to indicate their status.

In Celtic society, however, the position of women was vastly different.  There were female figures of supreme authority, including war leaders and they were often appointed ambassadors.  Celtic women had the right to succession, and could initiate divorces.  If a man had committed a crime and lost his rights, it did not affect the position of his wife.  A woman was responsible for her own debts and not those of her husband.  This did not change until after Julius Caesar conquered the Celts and the Romans forced them to convert to Roman Christianity.

The book goes into some detail about the role of Celtic women in religion until Rome noticed their presence in AD 515-520.  Rome exerted more influence in church matters, amd the role of women began to diminish.  The "law of the innocents", accepted by the Synod of Birrin AD 697, emancipated Celtic women from serving in battle.  The law forbade women to be warriers or military commanders.  The position on women in Celtic society had not degenerated to the same level as it had in other European cultures; however, it began a steady change from that point.  Women could still own property, and if a woman divorced she became entitled to half of the marriage wealth, a concept introduced into English law only in the closing decades of the twentieth century.

ANAM CHARA:  In the Celtic church, confession of sin was not obligatory and any confessing that was needed was made to a chosen "soul friend."  According to Father Joseph MacVeigh in "Renewing the Irish Church (1993)" -- The ‘soul friend’ (anam chara) who acted as a spiritual guide and counselor - not confessor - to young monks and converts was part of Druidic practice.  Sin and the need to confess it was something new to Celtic perceptions.  The role was usually filled by a druid.  In early Celtic Christian society, the position of soul-friend was usually filled by women.  In later life, as he spent more time in France and Italy and was influenced by Roman perceptions, Columbanus ordered that males could only confide in male soul-friends.

BANSHEES:  After Christianity achieved its dominance in the Celtic world, the Celtic gods were relegated to dwell in the hills.  In Irish, the word "sidhe" means mound or hill, and denoted the final dwelling places of the De Danaan, the Immortals, after their defeat by the Milesians.  The ancient gods, thus driven underground, were relegated in folk memory as aes sidhe, the people of the hills, or in later folklore as simply fairies.  The word sidhe is now the modern Irish word for fairies.  The most famous is the banshee (bean sidhe), the woman of the fairies whose wail and shriek portends a death, in later folklore.

BOYCOTT:  In ancient Celtic society, those who refused the Druids' judgment were ostracized.  The concept of ostracization, known in the Brehon law as dibert, survives in modern Irish as sligdhibert, the word of ostracization meaning, literally the way of banishment.  "ar dibirt ort!" would be a blunt way of telling one to "get lost."

In 1880 Captain Charles Cunningham Boycott (1832-1897) was an English agent for the estates of the Earl of Erne, at Lough Mask in County Mayo.  He had become symbolic of the colonial English landowners and their agents who, just twenty-five years before had, due to insensitive policies and uncaring greed, let an artificially induced famine spread through Ireland, causing a loss to its population in real terms of 2-1/2 millions between 1844-1848.  The Irish Land League, rejecting violence as a way of dealing with men like Boycott, decided to use the ancient Irish dibert or ostracization as a new social and political weapon.  The word "boycott" soon entered the English language following the success of the weapon.

CIRCLE OF PROSPERITY:  A survival of another Druidical ritual.  The daily course of the sun, bringing about the alternation of light and darkness and the succession of the seasons, was the most immediate example of the natural order of the universe.  In old Irish the universe was seen as something circular and the words for universe, cruinne and roth, signified that concept.  The circle of the universe served as the modus operandi for prosperity and increase, both spiritually and physically.  To imitate the course of the sun, to go right-handed, was to perform a ritual to bring beneficial results.  To go tuaithbel, or lefthand-wise, in the contrary direction, would be a
violation of the order of the universe and bring harm.

DAGDA: The Dagda was the "father of the gods" and the god of Druidism.  Son Ogma becomes the god of eloquence and poetry.  The Goddess Brigit (the exalted or high one) was a daughter of the Dagda and was a divinity of healing, poetry and arts and crafts. The Dagda appears as the patron of Irish Druidism.  He is visualized as a man carrying a gigantic club which he drags on wheels.  One end of his club can slay while the other can heal.  He has a black horse named Acéin, or Ocean, and his cauldron, called Undri, is one of the major treasures of the Dé Danaan, brought from the fabulous city of Murias.  It provides food so that no man went away from it hungry.  It is the "cauldron of plenty"  which later generations of Christianized Celts developed into the Holy Grail of Arthurian myth.  The Dagda also possesses a magic harp.

DIARMUID:  Diarmuid MacCearbaill, reigning between AD 545-568.  He is said to have had both Druids and Christian advisors at his court in Tara.  When one of Dairmuid’s men was killed by a chieftain named Aodh Guaire, related in fosterage to St. Ronán, Diarmuid sent his men to arrest Aodh.  St Ronán his hiim and so Diarmuid had Ronán arrested in his stead.

When Diarmuid’s wife Mughain had an affair with Flann Mac Dima, Diarmuid had Flann’s fortress burnt over his head.  Sorely wounded, Flann sought to avoid the flames by climing into a vat of water, where he drowned.

There are a couple of stories to explain what happened here.  Here’s the most interesting:  Beag Mac Dé, the Druid, prophesized that Diarmuid would be killed by Flann’s kinsman,. Aedh Dubh mac Suibni, in the house of Banbán of Ráith Bec, a small ring fort east of Antrin. His death would only be encompassed on the night when he wore a shirt grown from a single flax seed, when he drank ale brewed from one grain of corn, and when he ate pork from a sow which was never farrowed. The manner of his death would be by burning, by drowning and by the ridge-pole of a roof falling on his head.   The prophecy seemed so unlikely that Diarmuid scorned it, although he did have Aedh Dubh banished from Ireland and sought other ways to protect himself from any event by which the prophecy could come true.

However, a day arrived when Banbán invited the High King to a feast.  Diarmuid ignored the prophecy and went to his fortress.

At Banbán’s house, his host suggested that since the king’s wife, Muighain, had not accompanied him, his own daughter would "this night be your wife."  The girl brought Diarmuid a nightshirt, food and ale.  The prophecy began to be fulfilled.  Realizing his impending doom, Diarmuid sprang to the door.  Aedh Dubh was there and stabbed him.  Wounded, Diarmuid fled into the house.  Aedh Dubh’s men set fire to it.  Seeking to escape the flames, Diarmuid scrambled into a vat of ale.  A burning ridge-pole fell on his head.  The prophecy was fulfilled in all its aspects.

DRACONIAN:  The Greeks are said to have passed from a system of individual vengeance to a codified system when Draco, in 621 BC, was given extraordinary power to codify the laws of Athens for the first time, and devised new laws.  Demades (c. 380-319 BC, commented that the code was written in blood rather than ink, for it was a harsh code with the death penalty prescribed for many crimes, not only homicide (hence the word draconian coming into English).

FLATHEAD:  Eoghan of Munster met a Druid who realized from the horoscope that the King would be slain in his next battle, but if he conceived a son at that time, he would become a great and powerful king.  The Druid had a daughter named Moncha and he told her to sleep with Eoghan.  She became pregnant and Eoghan was killed.  Moncha, in order to prevent the birth occurring before the right planetary configuration, sat astride a rock in a stream.  When the child was born, at the right time, his head had been flattened by Moncha's pressing against the stone which had prevented his birth and he was called Fiachu Muilleathan, or the FLATHEAD.  The horoscope was then fulfilled

HALLOWEEN:  On one night of the year, the Otherworld became visible to mankind.  This was the feast of Samhain (31 October 1 November), when the gates to the Otherworld were opened and the inhabitants could set out to wreak vengeance on those living in this world who had wronged them.  The ancient belief survived into Christianity in a transmuted form as Hallowe’en, the evening of All Hallows, with All Hallows or All Saints’ Day being on 1 November.  The modern idea is that it is the night when witches and demons and spirits from Hell set out to ensnare unsuspecting souls.

HUNGER STRIKES:  The troscad is referred to in Irish sagas as well as laws, and when Christianity displaced the pagan religion, the troscad continued.  Some people fasted against the saints themselves to get them to give justice and wives also fasted against their erring husbands.  In the centuries of England’s relationship with Ireland, the Irish have continued the tradition of the troscad, which has become the political hunger strike.  The troscad was never entered into lightly and always with full knowledge of the seriousness of the final intent (death).

IRELAND:  Eire is the name of one of the triune goddesses; her sisters being Banba and Fotla.  Each goddess asked the Milesians to remember her by naming Ireland after her.  Banba and Fotla were often used as synonyms, particularly, in poetry, for Ireland.  But the Druid, Amairgen, promised the goddess Eire that the children of the Gael would use her name as the principal name of the country.

IRISH FUNERALS:  Druids had rituals for the funeral of a departed person.  In Ireland there was a feast, fled co-lige, followed by funeral games, cluiche caintech.  The whole was a form of celebration because the ancient Celts celebrated the rebirth of the dead one in the Otherworld.  At that time, it was common to loan someone money to be paid back "in the Otherworld."

KILDARE:  many ancient churches were built on the site of Druidic oaks.  Most famous are Bridid’s monastery at Cille Daire (Kildare - church of the oak), at Daire Maugh (Durrow - plain of the oaks), and Colmcille’s Daire Calgaich (Derry - the oak grove of Calgiach).

LEPRECHAUN:  Lugh, in Irish myth, was the son of Cian and Ethlinn, and was the god of all arts and crafts.  He was the greatest of all gods.  The Dagda (father of the gods) yeilds command to him at the second battle of Magh Tuireadh.  Lugh possessed many crafts, one of which was shoemaking.  In Ireland, as the old gods were driven underground by Christianity, Lugh diminished in people's minds, becoming simply a fairy craftsman - Lugh chromain "little stooping Lugh."  Now all that is left of him is the Anglicized version of Luch-chromain - the leprechaun, a fairy cobbler.

MORRIGAN:  The most famous war goddess was the Morrigan, sometimes called Morrigu "great queen."

MEADE:  The book mentions Medb of Connacht, the daughter of Conan of Cuala.  Her name means "an intoxicating liquor", and is the origin of the English mead.  An ancient poem says that no one can be king in Ireland unless they drink of the mead of Cuala.

OGHAM SCRIPT:  Ogma was the god of eloquence and literature, and a son of The Dagda.  He is credited with the invention of Ogham script, named after him, the earliest form of Irish writing.