VACARIO. – Roman-Byzantine jurist, known as *magister Vacarius*, born in Lombardy ca. 1115–20, died in England after 1198.
He studied the new legal science in Bologna under the disciples of Irnerius (v.). Around 1145 he settled in England at the invitation of the household of Theobald, Archbishop of Canterbury, to whom he belonged as an ordained *clericus*. He was the first to introduce the teaching of Roman jurisprudence to the island; after the death (1154) of King Stephen, who had forbidden it, he held a chair especially at Oxford, with which his fame is linked. After the death of Theobald (1161), he entered the service of the archiepiscopal curia of York under Roger, whom he helped to clear of the charge of complicity in the murder of St Thomas Becket, and later under Geoffrey Plantagenet. In 1198 Innocent III entrusted him with the preaching of the Crusade for the Holy Land in the province of York.
He wrote a scholastic compendium of the Justinian Code and Digest, with coordinating and explanatory glosses, in the early years of his teaching, ca. 1149, which was enriched with personal notes or those drawn from oral instruction: it was commonly called the *Liber pauperum*, because it was easily affordable for those students, henceforth called *pauperistae*, who lacked the means to procure the more expensive complete legislative texts.
In the *Summa de matrimonio*, composed ca. 1156, he treated as a civilian the question of the essence of the marriage contract, debated among the canonists of Bologna and the theologians of Paris, endorsing the Parisian view of *consensus* and identifying the perfecting element of the matrimonial act in the *traditio* or *mutua susceptio*. He also opposed the conciliatory tendency fashionable among the decretists. In the *De assumpto homine* (ms. in the University of Cambridge) and in other untraced pamphlets, he defended the reality of the human nature of Christ and the unity of the person. A broader field of discussion was opened to him in the *Liber contra multiplices et varios errores* (before 1177), in which he refuted the errors of his former fellow student U. SPERONI, UGO (v.), who had become a heresiarch, developing many and important theological themes. In keeping with his juridical spirit, V. defended traditional doctrine with conceptual precision and rigorous argumentation, alternating scriptural *auctoritates* and *rationes*, and frequently drawing on Roman law notions and examples.
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