St Lewina was a young British virgin who was martyred by Saxons on 24 July 687AD (whilst Theodore was 7th Archbishop of Canterbury). Following her death she was buried at Seaford, near Lewes in East Sussex.
In 1058, in order to preserve her relics from invading Danes, Bishop Edilin moved them to Saint Winnoc’s Abbey Church in Bergues in Flanders. (The relics of St Oswald and St Idaberga were also taken along with those of St Lewina to safety).
Her Feast Day and date of Martyrdom is 24 July (though I have also come across references to it being on 22 July).