St. Patrick, (flourished 5th century, Britain and Ireland; feast day March 17), patron saint and national apostle of Ireland, credited with bringing Christianity to Ireland and
probably responsible in part for the Christianization of the Picts and Anglo-Saxons. https://www.britannica.com/biography/Saint-Patrick
The Picts were in Scotland. The Angles and Saxons were in what is now called England. Whether Patrick had much if anything to do personally with Christianizing the Saxons is unlikely, but it is well known that Celtic missionaries carried the Word from Ireland to northern England in the century after Patrick is believed to have lived.