Due to the differing role of women in past society, special rules grew relating to the blazoning of arms for women. The rules for women and heraldry developed differently from place to place and there is no one single rule that applies everywhere. In general, arms of women were most likely depicted not on shields but on lozenges or ovals. Different rules exist that depend on the woman's marital status and a married woman would also often make use of her husband's arms in addition to those from her family. In both the English and the Scottish systems of heraldry these differences remain active. Characteristics Escutcheons, crests, and other heraldic elements Heraldry has its origins from associations with warfare and the age of chivalry. The traditional shield was also associated with war and so women did not usually display familial arms on escutcheons. Rather, they could display these on various other shapes: more commonly the lozenge, an oval, or a cartouche. The crest–a device that sits atop the shield on an armorial achievement–likewise was not accorded to heraldic devices of women as these had associations with warfare. Transmission In many heraldic traditions, arms generally are passed patrilineally. In other nations, in Canadian heraldry for example, women may inherit arms on an equal basis with their brothers (if any). Women in Canada may also transmit their arms to their heirs, regardless of sex. By tradition British Heraldry In English, Scottish and Northern Irish heraldry, a woman may bear arms by inheritance from her father or by grant to herself. When unmarried, she displays her arms on a lozenge (a diamond shape) or on an oval or oval-like shape. Traditionally, a woman does not display her arms on a shield, as the shield originated with knights and warfare, and is thus viewed as fitting for a man, but not a woman. When married, a woman has the option of uniting her arms with those of her husband in what are called marital arms; their arms are impaled, meaning they are placed side by side in the same shield, with those of the man on the dexter (left, as seen from the front) and those of his wife on the sinister (right, as seen from the front). If one spouse belongs to the higher ranks of an order of chivalry, and is thereby entitled to surround his or her arms with a circlet