Preface: Hello! I'd just like to start off by saying thank you for everyone who helped me with some of the ideas i'm using to put this timeline together. It's an Irewank/Eirewank, just to warn you! I'd also like to say that this is my first timeline and that i'm not a history expert at all, and that constructive criticism and suggestions are appreciated and welcomed! This first installment will have a slightly different format than the rest~
Prologue: The First Unification
Part One: Agricola and the Eblani
The history of Ireland, and by extension, all the lands under the Irish Commonwealth, goes back centuries. Centuries of non-unified and warring tribes stretch back farther than the records of that time. Historians to this day argue about uncertainties surrounding the earliest history of the great nation. What most historians agree on, however, is that the beginning of a unified Gaelic state started when Gnaeus Julius Agricola turned his sight towards Ireland, known by the Romans as Hibernia. Most scholars agree that it happened sometime during the late first century.
Agricola thought that the island of Hibernia could be easily subdued and held with a single Legion. And when a exiled Gaelic prince came to him, and in anger, told Agricola of most of the weaknesses of the tribes and kingdoms, it only confirmed Agricola's beliefs. The Roman general used this prince to his advantage, learning much about the Gaelic tribes and giving the prince snippets of information about the Empire itself. The two became close friends, and when Agricola asked him to return to his tribe and convince them to join Rome or be crushed, the prince obliged.
With the Roman legionaries plus natives of the island, Agricola was confident in his ability to quickly and easily take it. However, when he pleaded with the Roman government for permission to conquer the island, but was turned down. That should of been the end of it.. but it wasn't. Agricola still had his eyes on the prize. With an exiled Eblani prince at his side, he supplied the semi-loyal Gaelic tribe of Eblani with weapons and other supplies. By going through this prince, he managed to unify most of eastern and southern Hibernia into a single kingdom. The first legitimate unified Kingdom of Éireann had been formed. And the red headed prince, Féthnaid O'Rahilly, would start a dynasty that would last until modern times.
Part Two: An Empire Collapses
By the time the Western Roman Empire would collapse and be replaced by many smaller kingdoms and dukedoms, O'Rahilly Éireann stretched till the ocean on it's eastern, northern, and western borders. Only the much smaller Kingdom of Munster remained outside of their grasp. By 480, Éireann did not need the supplies or help of the empire anymore, so the fall did not harm them so much directly as it did indirectly. From the Empire's carcass, smaller territories would be carved out. Not every single one of these territories would remain on friendly terms with Éireann as the Empire did. In particular, the newly born kingdoms in Britannia would bring trouble.
The other main problem the people of Éireann had with the fall of the Empire was that the fall of Rome seemed like the fall of the Pope. And by 480, paganism had been all but eliminated on the island. Earlier, sometime around 460, a Roman-Briton by the name of St. Patrick had come to the island and converted most of the peoples to the Roman's religion. In twenty years the island had absorbed the belief like a sponge absorbs water. Yes, Éireann considered herself catholic, with it's spirit under the Pope. For a short time, the lack of communication with Rome had weakened the faith of her people. However, within the year, an envoy from Constantinople had come and assured the Archbishop of Éireann, a fellow by the name of Sil Uidir, that the Catholic Church indeed would live on.
The Kingdom of Éireann would flourish as it unconsciously shifted into a feudal system along with it's neighbors, including the Britons. The O'Rahilly Dynasty watched with glee as the much weaker Briton kingdoms warred about, weakening each other. And later on, when the Danes raided Britannia, Éireann was strong enough to defend itself. Kingdoms such as Cornwall or Wessex were not. It only became a problem for Éireann in the late 800s, when the Danish invaders conquered a rather large area of Britannia. The current high king, Cináed O'Rahilly, would have some trouble with the Vikings during his reign...
Afternote: I feel like it was worse than I thought it was going to be.

Anyways~ I used the Eblani (Eblanoi?) because they were around what would later be Dublin. I used Féthnaid because Agricola did meet a Gaelic prince, but as far as I could tell, who he was is lost to history. Again, i'm totally up for criticism and suggestions!
