As has been pointed out earlier, the use of the term "English" when referring to St. Patrick is anachronistic. I have heard it suggested that he was Pictish, too, for what it's worth. I should mention, though, that the use of "Irish" when referring to the Scoti is also anachronistic, since Ireland as a nation did not at that time exist. It is also quite incorrect to refer to Scoti in Scotland (as that country later became) as "Irish", just as it would be to refer to those Scoti who remained in mainland Europe as "Irish".

Pedantic, I know, but it's important to remember that this was a time of tribal migrations, and the "nation" as we understand it today did not really exist. It's also worth remembering that the Romano-Britons did not simply move lock stock and barrel to Wales and Cornwall (as they later became) when the Angles, Saxons and so on turned up; many stayed put and intermarried. There is a lot more Celtic blood in the average English person -and Anglo-Saxon and Norse blood in the "Celtic" nations- than is generally realised!

Malcolm