Mr. Köhler was little known to most Germans and a stranger to front-line politics before he won the presidency. His nomination was greeted by the mass-circulation daily Bild with the headline “Horst Who?” Mr. Köhler, who was head of state from 2004 to 2010, died Saturday morning in Berlin after a short illness, surrounded by his family, the office of current German President Frank-Walter Steinmeier said in a statement. BERLIN — Horst Köhler, a onetime head of the International Monetary Fund who became a popular German president before stunning the country by resigning abruptly in a flap over comments about...