A great deal of effort is expended in keeping the Muggles unaware of magic. Originally the two worlds co-existed; however, persecution of those with magic meant laws have been put in place over the centuries, designed to keep the existence of the magical world hidden from Muggles. The first and most important statute is the International Statute of Wizarding Secrecy of 1692. Enchantment of Muggle artefacts is forbidden; under-age wizards are restricted from using magic outside school, and any deliberate revelation of magical ability to the Muggle community is punishable. However, allowances are made for the use of magic in the presence of a Muggle in case of a life-threatening situation (for the wizard or the Muggle). These laws are enforced by the Ministry of Magic, while a special arm of it, the Obliviators, has the job of making certain that Muggles who have seen magic in action will be left with no "inconvenient" memories. Exceptions to the statute of secrecy include wizards' Muggle relatives and high-ranking political leaders; the Prime Minister of the United Kingdom, for instance.