The associated coat of arms for this name are recorded in J.B Rietstaps Armorial General. Illustrated by V & H.V Rolland's. This Monumental work took 23 years to complete and 85,000 coats of Arms are included in this work. This surname AASEN is a Norwegian and Portugese baptismal name, from a given name which was bestowed on someone who was born on the Feast of the Ascension of Christ. The name was rendered in medieval documents in the Latin form ASCENSIO. Other spellings of the name include ASENSIO, ASENJO, ASCENSAEO and ASCENSI. Portugese surnames share many of the features of Spanish surnames, in particular Arabic and Visigothic influence. A notable feature of Portugese surnames is the class of religious names referring to festivals of the church or attributes of the Virgin Mary. One respect in which Portugese names differ from those of the rest of the Iberian peninsular, is that some were adopted at a comparatively late date and honour saints who did not give rise to surnames in other languages. Portugese names typically have the ending 'eiro'. A notable member of the name was Ivar Andreas AASEN (1813-96) the Norwegian philologist, lexicographer and writer, born in Sunmore, the son of a peasant. A fervent nationalist, he was the creator of the 'national language' called LANDSMAL (later known as Nynorsk - New Norwegian, based on western Norwegian dialects. He published a 'Grammar of the Norwegian Dialects' in 1884, followed by a 'Dictionary of the Norwegian Dialects' in 1850. It was not until the 10th century that modern hereditary surnames first developed, and the use of fixed names spread, first to France, and then England, then to Germany and all of Europe. In these parts of Europe, the individual man was becoming more important, commerce was increasing and the exact identification of each man was becoming a necessity. Even today however, the Church does not recognise surnames. Baptisms and marriages are performed through use of the Christian name alone. Thus hereditary names as we know them today developed gradually during the 11th to the 15th century in the various European countries.