If ever there was an act of selfless generosity born of family love and loyalty, then this is it, the work of Honor O Brolchain.

The teacher, poet, writer and musician has edited a vast trove of diaries, notes and memoirs written and recorded by her grandmother, Geraldine Plunkett Dillon. She has transformed what must have been a formidable pile into an accessible, conversational personal record of the 1916 Rising and the War of Independence by a woman who was never far from the hub of historic happenings.

Geraldine Plunkett Dillon was the daughter of Count and Countess Plunkett and sister of Joseph Plunkett, signatory of the 1916 Proclamation, who was executed for his part in the rising.

The book that her grand-daughter has now gleaned from contemporary notes illuminates a dramatic period, together with the people of the time, both ordinary and illustrious.

Michael Collins was an intimate ("I asked Mick, if it was going ahead and he nodded"), de Valera ("Joe was ill, so de Valera and my brother Jack moved the ammunition to a safer place on the backs of bicycles"), Ernie O'Malley ("He was very pleasant company and very kind. He continued to be like this until he went to the US and got married when he seemed to change his nature completely"), Oscar Wilde and Speranza, Jack and "Willie" Yeats . . .

Plunkett Dillon's stories of growing up in a wealthy Catholic family, presided over by her eccentric and neglectful "Ma" and her much loved "Pa", Count Plunkett, is a colourful insight on a class and a way of life that have gone.

Although it will be mined by academics for its politics and its revolution, All In The Blood is also a valuable record of ordinary people and their ways. Typical is Plunkett Dillon's memory of being brought into College Green as a child to see "that old so-and-so Queen Victoria" pass by. "I was lifted off my feet by the crush. The women all around me were wearing enormous hats held on with huge hatpins with fancy tops and I saw a small boy holding a big bundle of these pins of all colours, which he had picked out of the hats."

Honor O Brolchain has rescued a kaleidoscope of history and experience from the attic of indifference. In doing so, she has given us a fine, historical and literary work.

And she has given her granny immortality.

Geraldine Plunkett Dillon, the fourth of seven children born to Count George Noble Plunkett and his wife Mary Josephine née Cranny, was an obsessional collector of family papers stretching back to 1850, and kept detailed notes and diaries of her own life up to her death at the age of 94 in 1986. The current memoirs finish at the end of the War of Independence. They have been edited by her granddaughter, Honor O Brolchain, who must have spent long hours researching papers that she describes as enough to fill three lorries.

Geraldine's account of her earlier days forms the core of the book. Geraldine was married to Prof Tom Dillon, who was professor of chemistry at University College (now NUI) Galway and who, like Geraldine's family, was active in the separatist movement in the early years of the last century.

The Plunkett family's wealth was established towards the end of the 19th century, when the Counts father, Pat Plunkett, and the Countess's father, Pat Cranny, entered the construction business. It was they who built more than 100 of the fine Victorian houses in south Dublin-on Palmerston Road, Belgrave Road, and many of the roads in Donnybrook and Ballsbridge-and thus helped to create probably the finest Victorian inner suburb in these islands. These properties finished in the tight hands of the Countess, a grip she retained until the time of her death at the age of 86. Little of this wealth was shared with her seven children during her long lifetime.

The Crannys and the Plunketts were among the first Catholic entrepreneurs to emerge from the rigours of Protestant domination. The Plunkett family was dysfunctional and many of its problems-which Geraldine records so frankly-were created by the Countess's unkindness to her own children. She was cantankerous, mean, capricious and dominating, and had a strong influence over the Count, who apparently did little to control her aberrant behaviour.

Geraldine's brother Joseph was one of the signatories of the 1916 Proclamation. He married Grace Gifford just before his execution. Like all the signatories of the 1916 Proclamation, Joe left behind an extended family that was steeped in the rhetoric of the Republic and thus passionately anti-Treaty. Two of his brothers remained active IRA members up to the second World War. The editor includes first-hand reminiscences of the turbulent period 1916-1921. Geraldine was obviously well known to all the nationalist leaders and their families. She attended the meeting of the First Dail in the Mansion House in January 1919, which she described as quiet and orderly, and without any evidence of triumphalism.

Geraldine moved to Galway in 1919 when her husband, Tom Dillon, was appointed to the university. She lived there to the full until his retirement about 30 years later. She describes the terror there, where the RIC and the Black and Tans were responsible for killings, burnings, the constant raiding of houses and the hassling of the local population. However, there is little information about any organised or formal military activity by the IRA. Her descriptions do not lack humour. Her husband, like the Plunketts, was a nationalist in the IRA and had spent time in Gloucester jail. On one occasion in Galway he escaped from the house when the Tans came to fetch him. He left with his trousers over his pyjamas but he lost his trousers while escaping. He eventually found refuge with a community of priests. He was cared for there but his presence was reported the following morning to the local bishop. The bishop was disturbed by the event, saying that it was regrettable for a religious institution to harbour him and this was not to happen again.

Padraic O'Maille's house in Connemara was a refuge for members of the IRA who were on the run. Apparently, 14 RIC officers travelling on bikes became suspicious at the house and its occupants. However, the RIC men were soon attacked by the occupants and a battle ensued that lasted "from 5am to 4pm". The police were soon reinforced by seven lorries of troops and an armoured car with a Rolls engine and machine guns. The district inspector was in charge. The house was taken but they had escaped. An armoured train was later sent as far as Clifden and aircraft joined in the search. "Thousands of soldiers and police were out." Some of her descriptions seem almost surreal.

Geraldine showed extraordinary energy in all her family and social affairs. She was an unquenchable recorder of her everyday life. She was strong in her views, passionate, outspoken, and probably argumentative, but she was also caring, generous and was fortunate to have a sense of humour to protect her from the frugality of her times, the stresses within a dysfunctional family, a somewhat unstable marriage and a dominating, intrusive and long living mother. The memoirs may be a little rambling at times, but thanks to excellent editing they do provide us with a good insight into the late 19th- and early 20th-century politics and social circumstances of Dublin and Ireland in one of the great transition times of the country's history. The editor, Honor O Brolchain, deserves our thanks. She had a Herculean task in dealing with such vast sources of material Above all, Geraldine Plunkett Dillon deserves our thanks for the remarkable archive she has left to posterity.

This is a remarkable book, full of colour and incident, a memoir of a chaotic well-to-do household presided over by the formidable erratic character that was Ma, otherwise known as Countess Pluntett, a living terror. The children of the family who grew into active nationalists, also became living terrors in the eyes of the British establishment.

The last time Geraldine Plunkett Dillon, mother of novelist Eilis Dillon, saw her brother Joe was when he placed a bomb in a tram and fired his Mauser pistol into it to blow it up. Geraldine was on the first day of her honeymoon. She had married UCD chemistry lecturer Thomas Dillon on Easter Sunday 1916.

The couple were in the Imperial Hotel right across from the GPO when, the next day, Pearse read the Proclamation of the Republic. This had been sighed by Geraldine's brother, Joe (Joseph Mary Plunkett), who in his new volunteer uniform was a player in the scene unfolding before the couple's eyes.

Tubercular and sickly for much of his life, Joe had already set the seal on his own death warrant as he went about his business in Sackville Street. Deeply involved in planning the rising, he was put up against a wall in Kilmainham and shot on May 4, the day after Pearse and Tomas McDonagh died facing their firing squads.

In a way, the Rising divides Geraldine Plunkett's narrative into two unequal parts, The second is more compressed and fraught as she witnesses the slow birth of a nation through blood and violence. Her mother and father were jailed and deported to England. She and her husband were both imprisoned.

Her brothers George and Jack were with Rory O'Connor in the Four Courts when the Civil War erupted and they remained active in the IRA until the 1940s, when they went on hunger strike while interned in the Curragh. Her sister Fiona was in Cumann na mBan and was also jailed.

The first part is an extraordinary story of two Catholic families, the Plunketts and the Crannys, their fortunes growing with the redbrick spread of Dublin. Geraldine's grandfathers Patrick Plunkett and Patrick Cranny built houses in what have become, in our time, some of the most desirable areas of the city.

They built homes for the growing middle classes on Belgrave Road, Belgrave Square, Palmerston Park and Palmerston Road as well as Marlborough Road, Wellington Road, Clyde Road and Elgin Road. Both men's lives straddled 1829, the critical year of Catholic Emancipation, and each was determined that his children should enter the professions and have opportunities denied to earlier generations of Irish people.

To modern eyes, the 20 years after emancipation seem dominated by the social winnowing that was the Great Famine, but Irish society was also developing and changing in other, more gradual and significant ways. Irish Catholics were like immigrants in their own land, trying to make their way against established interests in the trades and professions. As enterprising individuals such as Plunkett and Cranny moved into the category of voters, their numbers changed the balance of power-sometimes in a dramatic fashion.

The two rising families were joined when Geraldine's parents, George Noble Plunkett and Mary Josephine Cranny, second cousins, were married in 1884, not long after George (Pa) had been made a papal count. He had fallen in love with her when she was 14 and he was 21 though they were not married for many years.

"She was more or less forgotten about when she was growing up," Geraldine wrote. It may have been this experience that led Ma from time to time virtually to abandon her children or to take a hand in their lives with often foolish notions or violent outbursts.

For much of the narrative, drawn splendidly from handwritten copybooks filled with memoirs and from many other documents by her grand-daughter Honor O Brolchain, Geraldine lives in a household whose quixotic matriarch might beat them or ignore them or turn their world upside down, depending entirely on whim.

In one fearsome swoop when the seven children were living virtually wild in Kilternan Abbey, sometimes minded by servants, sometimes not, she ordered all their pups drowned.

Later, all the children's cats except for Geraldine's Squall-rag met the same fate. The children had inadequate clothes, sometimes had to make their own and might be packed off to various schools without uniforms or books. Fees frequently went unpaid.

In her business dealings the countess secretly owned a slum property off Abbey Street in Dublin, which she bought but on which she never paid the instalments. Similarly, she acquired Larkfield, where the present Sundrive Road meets Lower Kimmage Road, but never seems to have paid instalments on the mortgage there either. An opponent of organised labour, she, in her daughter's words "joined the army of people who underpaid on principle".

Pa, Count Plunkett, later minister for foreign affairs in the first Dail and minister for arts in the second, existed in a world of letters, art and nationalist fervour and appears as an altogether more benign, if distant figure.

Widely travelled, he had written a well-received book on Botticelli and included Oscar Wilde among his acquaintances. However, many years after the Wilde scandal, Ma in a fit burned the 50 or so letters Wilde had written him.

The wealth flowing through the Plunkett and Cranny families was astonishing even by todays standards. A marriage might see several properties being settled as a wedding gift; foreign travel was common; Count and Countess Plunkett took a two-year honeymoon; education and accomplishment were prized.

Yet many of the Plunkett children, feeling perhaps the stirrings of their father's nationalist sentiments abandoned the conservatism that might have been engendered by access to such capital and became radicalised nationalists.

All In The Blood is full of remarkable insights and social observations. Ma believed Geraldine was pregnant when she married Tommy, but apologised when her first child was born a year later, and Geraldine discusses the rumour that Grace Gifford, who married Joe at midnight on the eve of his execution, was pregnant but not by Joe.

She believed this rumour was put about by Dublin Castle to discredit the pair.

On Geraldine Plunkett Dillon's evidence, Grace Gifford was indeed pregnant but miscarried. "When I went into her bedroom I saw a large white chamber pot full of blood and foetus. She said nothing and I said nothing."

Buy it, read it.

Honor O Brolchain has edited her grandmother Geraldines reminiscences. Geraldine was the sister of Joseph Plunkett, one of the seven planners of the 1916 Rising (and husband of my great-aunt Grace, if I may declare an interest). Her memoirs make your jaw drop, the circumstances of her childhood were so horrible. Her mother, Countess Plunkett, was totally bats. She was greedy and money-grubbing, and she was unbelievably nasty to her children. There are descriptions of her abandoning her children in far-flung homes, and simply forgetting-or not bothering-to supply them with food or money. She played favourites ruthlessly. Geraldine did well, because she decided to be a doctor, and this was an approved move. Joe, who got TB, possibly at least partly through her neglect, was alternately starved and indulged.

But its not just the story of an ordinarily vicious childhood: this is also an account of the people involved in the Rising. My grandfather is warmly described: "As soon as Tomás came into our house everyone was a friend of his. He had a pleasant, intelligent face and was always smiling, and you had the impression that he was always thinking about what you were saying."

And Grace is here. But this is the whimsy, droopy, moony, romantic creature, the flame-haired spéirbhean of song and story. Its not the Grace our own family knew, who was a funny, kind, sensible professional woman.

Joe Plunkett made the basic mistake-if he'd known his mother-of instructing Grace in his last letter that it was her duty to inherit his property, an instruction that proved disastrous to everyone involved.

These memoirs are the only source of the rumour that Grace was pregnant and subsequently miscarried-a highly unlikely story, given Graces personality. She wouldn't have been likely to hide such a thing. Its unfortunate that the book includes this claim, but fails to reprint the rebuttal by Seoirse Plunkett, who wrote to the newspapers indignantly when his sister first made the claim.

The memoirs, while showing what my mother used to call the Plunkett love of romancing, are a brilliant insight into the time, and the group of young intellectuals and activists who got together to free their country from occupation. These are the vivid memories of someone who was actually around at the time, and reading them you feel as if you're in the fields at Larkfield, the revolutionaries training, a dog romping around, and the Countess looking to make trouble and profit.

Its apparently selling like hotcakes, and it certainly should. Honor O Brolchain has done a brilliant job of editing and shaping the memoirs into a riveting book.

This book is a treasure trove for historians. It is beautifully shaped, superbly illustrated and reads like a best seller. Honor O Brolchain is to be congratulated for her splendid editing and for making generally accessible the best of the vast corpus of records and writing left to posterity by the truly remarkable Geraldine Plunkett Dillon.

A family and the nation's call