If you know about St. Kassiani chances are you are from an Orthodox background or you are just very well versed in saints.
She lived in the ninth century. She was born in Constantinople but ended up living on the Greek Island of Kasos. Her hymns are still used in the Byzantine liturgy today. There is a much longer write up about here here
It is always exciting to come across new Saints, especially when they are influential women. (The Church has tended to favor male writers when making Saints).
This is one of her prayers/poems.
O Thou who givest sleep, and ease from toil
To those whom daylight calls to labor still,
Grant thou to me, O Christ, Thou Word of God,
Sleep light and gentle, swift to come and go,
And pure from fancy visions profitless,
But filled with dreams of all things fair and good.
Then rouse me up, what time the clapper sounds,
Alert and sober, fit for sacred song.
Set well my feet to praise Thee while I go,
From evil spirits, keep my spirit free,
And purify my tongue to harmony,
To sing and magnify Thy glorious might;
That rising early after perfect rest
I may behold the light of Thy commands.