ADALBERTO, archbishop of MAINZ. - Son of Count Sieghard of Saarbrücken, he was chancellor to Henry V, king of Germany. He was elected archbishop in 1109 and in the same year accompanied the embassy sent by the king to Rome, to Paschal II. On 15 August 1111 he obtained the bishopric of Mainz, but then suddenly fell into the king’s disfavour and in December 1112 was arrested at Langendorf and thrown into prison, from which he was not released until 1115.
On 26 December of that year he received episcopal consecration at Cologne from Bishop Otto of Bamberg. He died on 25 June 1137 and was buried in the cathedral of Mainz.
BIBL.: PL 166, 1318; 172, 1135; F. Kolpe, Erzbischof Adalbert I von Mainz und Heinrich V, Heidelberg 1872, p. 149; Bohmer-Will, Regesta archiepiscoporum Moguntinensium, I, Innsbruck 1887, pp. 249-306; G. Meyer V. Knonau, Jahrbücher des deutschen Reiches unter Heinrich IV, in Heinrich V, vol. VIII, Leipzig 1904-19. Emma Santovito