Saint Clarus

On this date, about 894, Saint Clarus was martyred. Clarus was of English extraction, and was murdered at the behest of a local noble woman, described historically as lewd and impious. The village where Clarus was martyred, on the Epte River in France, bears his name. Clarus is one derivation of the St. Clair, Sinclair family names.

Scott writes of the St. Clair faimly often, including in the Lay of the Last Minstrel. Scott is very familiar with Roslin Chapel, which has become popular now with the publication of Dan Brown's "Da Vinci Code".
...
"So still they blaze when fate is nigh,
The lordly line of high St. Clair.

There are twenty of Roslin's barons bold,
Lie buried within that proud Chapelle..."