In our timeline, the 1798 Rebellion in Ireland led to the Act of Union. This, and many other factors, led to Ireland becoming impoverished, while the rest of the UK became the workshop of the world. In some ways, it also led to the Ireland we see today, divided and bailed out.
But, what if the 1798 rebellion had been successful? What if Wolfe Tone, Henry John McCracken, John Murphy and others had succeeded in freeing Ireland from Britain's grip? What if, after that, Ireland went on to unite the rest of the Celtic lands, and bring Scandinavia, Iberia, Italy, and western and southern France under the Tricolour? What if we had an independent Ireland?