Medieval Europe characterizes what we think of as feudalism, but many of the inner workings, such as who owns what and why, go unnoticed. Originally, feudums were just military items and goods, such as armor, weaponry, and horses. By A.D. 1000, feudums evolved into pieces of land known as fiefs. Since feudal Europe relied heavily on its agriculture, wealth was derived from land. Land, therefore, became a means of improving one's status. That meant that a fief was not only a gift bestowed to a vassal by his lord, but it was a way to turn a vassal into a member of the upper class, as became prevalent over time. In the marriage of nobles, a dowry of land was given to the husband, so that he would receive land from his family as well as from his wife's family. Fiefs were granted to a vassal only for the lifetime of that vassal. However, it became the norm for a son to inherit the title of his father. In fact, this became so common that the practice of primogeniture, of the bequeathing of land and duties to the eldest son of a family became established.