This one was a gift from a bookbinding customer (Swiss American) from several years ago. It is a Swiss National Celebration postcard of 1916 (Mi # P52 01).
Between 1910 and 1937 Switzerland issued special postcards annually on August 1 to celebrate National Day, the day of founding in 1291. Sometimes just one picture design was produced, and sometimes as many as five (1920). For 1916, there are two, so the Michel "01" on the cat. # signifies that this is the card which depicts "Ceres stopping Mars, the god of war".
"Bruder Klaus" shown on the card opposite the 5c William Tell indicum, represents Nicholas of Fluehe (1417-1487), known as Brother Klaus, the patron saint of Switzerland. He was known as a man of complete moral integrity. The trilingual inscription on the bottom of the card states "for the troubled soldiers". Although Switzerland remained neutral throughout WWI, the call to active duty of the country's young men must have caused some hardship for them.