The Low Countries were great centres of heraldry in medieval times. One of the famous armorials is the Gelre Armorial or "Wapenboek", written between 1370 and 1414. Coats of arms in the Netherlands were not controlled by an official heraldic system like the two in the United Kingdom, nor were they used solely by noble families. Any person could develop and use a coat of arms if they wished to do so, provided they did not usurp someone else's arms, and historically, this right was enshrined in Roman Dutch law. As a result, many merchant families had coats of arms even though they were not members of the nobility. These are sometimes referred to as "burgher arms," and it is thought that most arms of this type were adopted while the Netherlands was a republic (1581–1806). This heraldic tradition was also exported to the erstwhile Dutch colonies. Dutch heraldry is characterised by its simple and rather sober style, and in this sense, is closer to its medieval origins than the elaborate styles which developed in other heraldic traditions.