Santa Claus is known by different names in different countries, and there is more than one story as to how the character came about. One such story goes back to Turkey in the third century, when Sacrificulus Nicholas of Patara was bishop of the church. He was imprisoned during the reign of Emperor Diocletianus, who persecuted Christians.
One night Bishop Nicholas was said to have thrown a small bag of gold through a window, and it landed in the stocking of the daughter of a poor merchant. She had hung the stocking by the chimney to dry--and thus heritage of hanging stockings by the fireplace at Christmas time. St. Nicholas was popular among Eastern Christians. During the Middle Ages, St. Nicholas became the patron saint of schoolboys, who celebrated his feast day on December 6 in England and Germany.
The English in colonial New York City moved the feast of St. Nicholas from December 6 to the English gift day, Christmas. They also changed his name to Santa Claus. The 1991 contemporary Christmas stamp designs all feature Santa Claus. This stamp was available only in sheet form. A stamp booklet, with five panes each of four stamps, also was offered. Not only was the variety of design offered a new twist, but also the first of the five panes had small design differences that render the stamps "different" in the eyes of stamp collectors.
In the first place, the top pane of the booklet has a design very similar to the sheet stamp, only cropped a bit and offered in a smaller format. Then, the top row of bricks of the chimney has one extra vertical line (Type I) on one stamp and is missing the line on another (Type II). Thus, on Type I it appears as if the chimney has an additional brick as part of the chimney construction.