Today is the Feast of St. Denis (Dionysius in Latin), Martyr and first Bishop of Paris, France. Pope St. Fabian dispatched Denis as a missionary to Gaul in the mid-third century. Denis and his companions, Sts. Rusticus and Eleutherius, for their part, shed their blood for Christ during either the Decian persecution around 250AD or that of Valerian in 258 AD. The place of their martyrdom was the hill of Montmartre.
Image of St. Denis (left) from the Nuremberg Chronicles, and (right) from a portal of Notre Dame.
Legend has it that St. Denis, after being beheaded, picked up his head and walked some distance to the site of the Basilica of St. Denis -- hence his frequent presentation in art holding his own head.
For more on the Saint you can visit:
Patron Saints Index St. Denis of Paris
Old Catholic Encyclopedia: St. Denis
Facade of the Basilica of St. Denis.
Built on the site of a an earlier church, the Basilica of St. Denis was first constructed by orders of the Frankish King Dagobert I (reigned 629-634AD), and would house the relics of St. Denis. This site of pilgrimage would also end up being the burial place of the Kings of France from the 10th through 18th century. The would be coronated at the Catherdral of Rheims (the see of St. Remy or Remigius), but they would be buried here at St. Denis, near Paris.
Interior of the Basilica of St. Denis.
The great Abbot Suger (+1151AD) began a project in 1135AD to remodel the Basilica, and giving rise to a new form of architecture: Gothic. It is an architectural masterpiece. You can read the Abbot's account of his renovations here: http://www.fordham.edu/halsall/source/sugar.html
With the exception of but three, every King of France from Clovis I (+511AD) to Louis XVIII (+1824AD) is buried in this sacred place. A couple of the monuments are pictured below:
Monument of King Louis XII (+1515AD) and his Queen, Anne of Brittany.
Monument of King Louis XVI (+1793AD) and his Queen, Marie Antoinette.