Adalbert of Mainz

Adalbert I
Archbishop of Mainz
Sketch of the seal of Adalbert on a falsified document from 1174-1211
Church	Catholic Church
Diocese	Electorate of Mainz
In office	1111–1137
Predecessor	Ruthard
Successor	Adalbert II
Personal details
Died	June 23, 1137

Adalbert I von Saarbrücken (died June 23, 1137) was Archbishop-Elector of Mainz from 1111 until his death. He played a key role in opposing Henry V, Holy Roman Emperor, during the Investiture Controversy, and secured the election of Lothair III rather than Henry V's chosen heir in 1125, causing later Holy Roman Emperors to make concessions in order to maintain hereditary monarchy.