St Margaret of Scotland
O God, the Ruler of all, who didst call Thy servant Margaret to an earthly throne and gavest to her both zeal for Thy Church and love for Thy people, that she might advance Thy heavenly kingdom: mercifully grant that we who commemorate her this day may be fruitful in good works and, with her prayers, attain to the glorious crown of Thy Saints; through Jesus Christ Thy Son our Lord, who liveth and reigneth with Thee, in the unity of the Holy Ghost, one God, now and always and forever. Amen.
(I found the picture on the Wikipedia site here. By Edward Burne-Jones it says, but it doesn't give the provenance. It would be interesting to know. You can click on it to get a better, i.e., larger, view.)