Theobald I was the Duke of Spoleto from 928 to his death. He was the son of Boniface II, former duke, and member of the line of the Hucpoldings, a house of Frankish Ripuarian origin that built its fortunes in Italy since the 9th century. Theobald was an unscrupulous prince, even for his age, and his career is one of constantly changing alliances as the political winds of central and southern Italy changed direction.

In 929, Theobald joined Landulf I of Benevento

Landulf I of Benevento

Landulf I , sometimes called Antipater, was a Lombard nobleman and the Prince of Benevento and of Capua from 12 January 901, when his father, Atenulf I, prince of Capua and conqueror of Benevento, associated his with him in power...

 and Guaimar II of Salerno

Guaimar II of Salerno

Guaimar II was the Lombard prince of Salerno from 901, when his father retired to a monastery, to his death. His father was Guaimar I and his mother was Itta. He was associated with his father in the principality from 893...

 in a series of joint attacks against Byzantine

Byzantine Empire

The Byzantine Empire was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the Roman Empire or Romania to its inhabitants and neighbours, the Empire was the direct continuation of the Ancient Roman State...

 Campania

Campania

Campania is a region in southern Italy. The region has a population of around 5.8 million people, making it the second-most-populous region of Italy; its total area of 13,590 km² makes it the most densely populated region in the country...

, Apulia

Apulia

Apulia is a region in Southern Italy bordering the Adriatic Sea in the east, the Ionian Sea to the southeast, and the Strait of Òtranto and Gulf of Taranto in the south. Its most southern portion, known as Salento peninsula, forms a high heel on the "boot" of Italy. The region comprises , and...

, and Calabria

Calabria

Calabria , in antiquity known as Bruttium, is a region in southern Italy, south of Naples, located at the "toe" of the Italian Peninsula. The capital city of Calabria is Catanzaro....

. Theobald was detrimental to the others' cooperation and all three were unsuccessful and Guaimar returned to his earlier Greek allegiance.

Theobald also allied with Docibilis II of Gaeta

Docibilis II of Gaeta

Docibilis II was the ruler of Gaeta, in one capacity or another, from 906 until his death. He was the son of the hypatus John I, who made him co-ruler in 906 or thereabouts....

 against the Greeks.