World War One Diary for Wednesday, March 21, 1917:
North Sea: US tanker Healdton sunk (20 die) by U-boat in Holland safety zone.
USA: French Military Mission sails for New York.
Belgium: German decree partitions country with centres at Brussels and Namur; Flemish official language in West, French in Walloon districts.
Oise: French Third Army occupies Tergnier on Crozat Canal, fights its way across on March 22.