1911 Encyclopædia Britannica/Lothair I.
LOTHAIR I. (795-855), Roman emperor, was the eldest son
of the emperor Louis I., and his wife Irmengarde. Little is
known of his early life, which was probably passed at the court
of his grandfather Charlemagne, until 815 when he became
ruler of Bavaria. When Louis in 817 divided the Empire between
his sons, Lothair was crowned joint emperor at Aix-la-Chapelle
and given a certain superiority over his brothers. In 821 he
married Irmengarde (d. 851), daughter of Hugo, count of Tours;
in 822 undertook the government of Italy; and, on the 5th of
April 823, was crowned emperor by Pope Paschal I. at Rome.
In November 824 he promulgated a statute concerning the
relations of pope and emperor which reserved the supreme
power to the secular potentate, and he afterwards issued various
ordinances for the good government of Italy. On his return to
his father’s court his stepmother Judith won his consent to her
plan for securing a kingdom for her son Charles, a scheme which
was carried out in 829. Lothair, however, soon changed his
attitude, and spent the succeeding decade in constant strife
over the division of the Empire with his father. He was
alterneately master of the Empire, and banished and confined to Italy;
at one time taking up arms in alliance with his brothers and
at another fighting against them; whilst the bounds of his
appointed kingdom were in turn extended and reduced. When
Louis was dying in 840, he sent the imperial insignia to Lothair,
who, disregarding the various partitions, claimed the whole
of the Empire. Negotiations with his brother Louis and his
half-brother Charles, both of whom armed to resist this claim,
were followed by an alliance of the younger brothers against
Lothair. A decisive battle was fought at Fontenoy on the 25th
of June 841, when, in spite of his personal gallantry, Lothair
was defeated and fled to Aix. With fresh troops he entered
upon a war of plunder, but the forces of his brothers were too
strong for him, and taking with him such treasure as he could
collect, he abandoned to them his capital. Efforts to make
peace were begun, and in June 842 the brothers met on an
island in the Sâone, and agreed to an arrangement which
developed, after much difficulty and delay, into the treaty of
Verdun signed in August 843. By this Lothair received Italy
and the imperial title, together with a stretch of land between
the North and Mediterranean Seas lying along the valleys of
the Rhine and the Rhone. He soon abandoned Italy to his
eldest son, Louis, and remained in his new kingdom, engaged
in alternate quarrels and reconciliations with his brothers, and
in futile efforts to defend his lands from the attacks of the
Normans and the Saracens. In 855 he became seriously ill,
and despairing of recovery renounced the throne, divided his
lands between his three sons, and on the 23rd of September
entered the monastery of Prüm, where he died six days later.
He was buried at Prüm, where his remains were found in 1860.
Lothair was entirely untrustworthy and quite unable to maintain
either the unity or the dignity of the empire of Charlemagne.
See “Annales Fuldenses”; Nithard, “Historiarum Libri,” both in the Monumenta Germaniae historica. Scriptores, Bände i. and ii. (Hanover and Berlin, 1826 fol.); E. Mühlbacher, Die Regesten des Kaiserreichs unter den Karolingern (Innsbruck, 1881); E. Dümmler, Geschichte des ostfränkischen Reichs (Leipzig, 1887-1888); B. Simson, Jahrbücher des deutschen Reiches unter Ludwig dem Frommen (Leipzig, 1874-1876).