Smaller European nations usually modelled their documents on those of the papacy, the empire, France, or England. The influence of papal letters and privileges can be observed particularly in Aragon, Castile, and Portugal, while German royal diplomas served as models in Bohemia (which was part of the empire), Hungary, and Poland. Because of the close political ties between the two kingdoms, Anglo-Saxon influence can be traced in the seal of the royal Danish documents during the 11th century, but, in the course of the 12th century, royal and princely German documents became the models for Danish as well as Swedish royal documents. Norwegian royal documents were modelled on Anglo-Saxon writs, probably as a result of the influence of English missionaries working in Norway from the early 11th century. The Norwegian writs were drawn up in the vernacular. The chancery of the Norman rulers of southern Italy and Sicily was highly developed. Influenced by the form of papal documents, the Norman documents comprise mainly privileges, either formal (with rota, witnesses, and gold bull) or simple (with rota, leaden bull, or wax seal), and mandates. They all have a detailed dateline that includes the name of the chancellor or other high court officials, the number of years since the birth of Christ, the regnal year of the king, and the apprecatio. The mandates are more simply executed. They lack the invocatio and start out with a simple intitulatio and inscriptio that ends with a salutation clause. There is neither arenga nor corroboratio, but there is a command clause in the text. The dating consists only of the place of issue, the day of the month, and the indictio. There is no rota or signature. The seal is of red wax. The head of the royal chancery of the Norman kingdom of Sicily was the chancellor, a layman who was an influential court official. The notaries who drafted and wrote the documents were also laymen. Because the German Hohenstaufen emperors also ruled in Sicily from 1194 to 1250, Norman chancery practice influenced subsequent German documents.