In 1497, shortly after inheriting the governance of the realm, King Manuel I summoned representatives of the municipalities for the purpose of discussing the weight reform. We know that the reform was concluded before the end of the century because the new standards were produced in 1499 and the new charter of Lisbon of 1500 was already based on the new system. This new system derives from a notion introduced by King João II, and it is based on a quintal of 128 arráteis of 16 ounces each.
The mark (reproduced along with the other weights that belong to the standard set and also in a larger size), should be similar to the mark of Cologne, which King João II defined as the standard, but more recent measurements proved it weighed 229 g (10 g lighter than the mark of Cologne). The horse-load was the equivalent of 10 arrobas.