In common with other European countries Spain developed a diplomatic service in this period. The sending of special embassies and the making of treaties had been customary since ancient times, but the practice of appointing ministers to reside at foreign courts and that of receiving those sent from abroad did not begin in Spain until the reign of Charles I. The initiative had come earlier from the Italian republics. From this time forward Spanish diplomacy, like that of other countries, took on a modern form, and ambassadors sent reports about the state of the countries to which they were accredited, strove to obtain advantages for Spain, endeavored to check the intrigues of the ambassadors of other nations, and made treaties. The use of spies as an auxiliary to ambassadorial work was general. For a time Spanish diplomacy enjoyed a high reputation for success, but in the later seventeenth century it was quite overshadowed by the French.
[Sidenote: The _Nueva Recopilación_ and other codes.]
The absolutism of the monarchy, its bureaucratic character, and the instinct of the _letrados_ for reducing everything to rules and regulations produced an abundance of legislation, much of which was exceedingly minute in detail and casual in subject-matter. It was natural therefore that there should be a desire for a fresh codification, and this at length took shape in a compilation by Bartolomé de Arrieta in 1567 of the _Nueva Recopilación_ (New Compendium, or Compilation), so-called with reference to the code of Montalvo, its predecessor, of the period of the Catholic Kings. The new collection, which was for Castile only, filled nine volumes, and amounted to little more than an elaboration of the _Ordenanzas_ of Montalvo, with the addition of laws enacted since 1484. It contained the same defects, omitting many royal orders or petitions of the _Cortes_ which had been granted, neglecting to eliminate obsolete laws, and failing to correct others whose text contained errors. Furthermore, in perpetuating the hierarchy of legal sources which had been established in the _Leyes de Toro_ it failed to distinguish between laws in the so-called supplementary codes (such as the _Partidas_) which were indeed supplementary or obsolete and those which had in fact come to be in force as the principal law. As a result the _Nueva Recopilación_ was generally discredited, and the Roman law of the _Partidas_, or even of the code of Justinian, was cited in preference. The force of government maintained the new code, however, and it ran through four more editions,--1581, 1592, 1598, and 1640,--and in each case added legislation since the preceding publication. The zeal for codification found expression also in Aragon, Catalonia, Vizcaya, and Guipúzcoa, while the laws with regard to the Americas were gathered together, after various lesser publications had been made in earlier times, in the _Recopilación de las Leyes de Indias_, first issued in 1680. The tendency toward the legal unity of the peninsula was not systematically striven for by the kings, since the variety in private law did not greatly affect their political sovereignty. Nevertheless, something was accomplished along these lines, and within each separate unit a great deal was effected. Thus, in Castile many of the former privileges which made for a division into classes and for consequent differences in the law were done away with, and the same process, though on a smaller scale, made itself felt in the other kingdoms of the peninsula.