During the Middle Ages, Pommern (Pomerania in English) was an important region with powerful dukes. Today, Pommern lies in two countries. Vorpommern is in Germany and Hinterpommern in Poland.
At the end of the 12th century, Pommern became a part of the Roman-German Empire. During most parts of the Middle Ages, powerful dukes lived in Stettin which was the largest town. The dukes were very influential in the Baltic region. They tried to assert their position against neighbouring principalities, which sometimes led to war.
At the end of the 14th century, a duke named Vartislav VII ruled Pommern. He was married to Maria, who was the niece of Queen Margareta. They had a son called Bogislav. When Queen Margareta needed a new king for Denmark, Norway and Sweden, she turned to Pommern. Her niece had recently died and six-year-old Bogislav was motherless. Margareta adopted the boy, called him Erik and made him King of the greatest realm in Europe. In this way, the son of a duke in Pommern became, for some time, the mightiest ruler in Europe.
Read more about Erik of Pommern at "People in Power"