The Carolingian monarchs also used metal _bullae_. None of Charlemagne's have survived, but there are still extant leaden examples of Charles the Bald. The use of lead was not persisted in either in the chancery of France or in that of Germany. Golden _bullae_ were employed on special occasions by both popes and temporal monarchs; for example, they were attached to the confirmations of the elections of the emperors in the 12th and 13th centuries; the bull of Leo X. conferring the title of Defender of the Faith on Henry VIII. in 1524, and the deed of alliance between Henry and Francis I. in 1527, had golden _bullae_; and other examples could be cited. But lead has always been the common metal to be thus employed. In the southern countries of Europe, where the warmth of the climate renders wax an undesirable material, leaden _bullae_ have been in ordinary use, not only in Italy but also in the Peninsula, in southern France, and in the Latin East (see SEALS).
The necessity of conforming to exact phraseology in diplomas and of observing regularity in expressing formulas naturally led to the compilation of formularies. From the early middle ages the art of composition, not only of charters but also of general correspondence, was commonly taught in the monasteries. The teacher was the _dictator_, his method of teaching was described by the verb _dictare_, and his teaching was _dictamen_ or the _ars dictaminis_. For the use of these monastic schools, formularies and manuals comprising formulas and models for the composition of the various acts and documents soon became indispensable. At a later stage such formularies developed into the models and treatises for epistolary style which have had their imitations even in modern times. The widespread use of the formularies had the advantage of imposing a certain degree of uniformity on the phrasing of documents of the western nations of Europe. Those compilations which are of an earlier period than the 11th century have been systematically examined and are published; those of more recent date still remain to be thoroughly edited. The early formularies are of the simpler kind, being collections of formulas without dissertation. The _Formulae Marculfi_, compiled by the monk Marculf about the year 650, was the most important work of this nature of the Merovingian period and became the official formulary of the time; and it continued in use in a revised edition in the early Carolingian chancery. Of the same period there are extant formularies compiled at various centres, such as Angers, Tours, Bourges, Sens, Reichenau, St Gall, Salzburg, Passau, Regensburg, Cordova, &c. (see Giry, _Manuel de diplomatique_, pp. 482-488). The _Liber diurnus Romanorum Pontificum_ was compiled in the 7th and 8th centuries, and was employed in the papal chancery to the end of the 11th century. Of the more developed treatises and manuals of epistolary rhetoric which succeeded, and which originated in Italy, the earliest example was the _Breviarium de dictamine_ of the monk Alberic of Monte Cassino, compiled about the year 1075. Another well-known work, the _Rationes dictandi_, is also attributed to the same author. Of later date was the _Ars dictaminis_ of Bernard of Chartres of the 12th century. Among special works on formularies are: E. de Rozière, _Recueil général des formules usitées dans l'empire des Francs_ (3 vols., Paris, 1861-1871); K. Zeumer, _Formulae Merovingici et Karolini aevi_ (Hanover, 1886); and L. Rockinger, _Briefsteller und Formelbücher des 11 bis. 14 Jahrhunderts_ (Munich, 1863-1864).