New Albion, OTL New Zealand, was settled ~1300 by the Maori. Around 1350, the last wave of immigrants came from the Society Islands.
In 1704, English ships went west from Cape Hoorn, (re-)discovered Australia and New Zealand, which were called Antipodia and New Albion respectively. England took claim of these lands, but for quite some while they stayed in the shadow of the English colonies in North and South Atlantis. Immigration only grew after Britain lost the anti-British War.
1838, after king Philip had been killed in the English revolution, and the Revolutionaries declared the British republic, the Royal Family under his successor George I fled to New Albion, and the pope went with them. In 1839, his admiral Carleton swore to retake Britain for the monarchy and collected the British navy in the Pacific, went to the North Sea and prepared for a strike against London, but was defeated in the end.