Poppo of Treffen was the fifty-seventh patriarch of Aquileia

Patriarch of Aquileia

The Patriarch of Aquileia was an office in the Roman Catholic Church. During the Middle Ages the Patriarchate of Aquileia was a temporal state in Northern Italy. The Patriarchate of Aquileia as a church office was suppressed in 1752....

 from 1019 to 1045.

In 1020, Poppo commanded the smallest of three armies which Emperor Henry II (who had appointed him as patriarch) led through Italy. Poppo followed the Apennines

Apennine mountains

The Apennines or Apennine Mountains or Greek oros but just as often used alone as a noun. The ancient Greeks and Romans typically but not always used "mountain" in the singular to mean one or a range; thus, "the Apennine mountain" refers to the entire chain and is translated "the Apennine...

 and joined the other divisions to besiege Troia, the new fortress of the Byzantine catepan

Catapanate of Italy

The Catepanate of Italy was a province of the Byzantine Empire, comprising mainland Italy south of a line drawn from Monte Gargano to the Gulf of Salerno. Amalfi and Naples, although north of that line, maintained allegiance to Constantinople through the catepan...

 Basil Boiannes. The siege failed and all parties returned home.

In 1027, Poppo entered and sacked Grado

Grado, Italy

Grado is a town and comune in the north-eastern Italian region of Friuli-Venezia Giulia, located on a peninsula of the Adriatic Sea between Venice and Trieste....

, the rival patriarchate

Patriarchate

A patriarchate is the office or jurisdiction of a patriarch. A patriarch, as the term is used here, is either* one of the highest-ranking bishops in Eastern Orthodoxy, earlier, the five that were included in the Pentarchy: Rome, Constantinople, Alexandria, Antioch, and Jerusalem, but now nine,...

 of northern Italy. Indeed, Poppo's reign appeared to see the ultimate victory for Aquileia. On 6 April, Pope John XIX

Pope John XIX

Pope John XIX , born Romanus, was Pope from 1024 to 1032.He succeeded his brother, Pope Benedict VIII , both being members of the powerful house of Tusculum...

 held a Lateran

Lateran

Lateran and Laterano are the shared names of several architectural projects throughout Rome. The properties were once owned by the Lateranus family of the former Roman Empire...

 synod in which he declared for Aquileia, giving its bishop the patriarchal dignity and putting the bishop of Grado under his jurisdiction. The patriarch took precedence over all Italian bishops, in fact. In 1029, John revoked his decision and reaffirmed all the dignities of Grado. In 1044, Poppo reentered and sacked Grado.

Poppo later consecrated the new large cathedral at Aquileia

Aquileia

Aquileia is an ancient Roman city in what is now Italy, at the head of the Adriatic at the edge of the lagoons, about 10 km from the sea, on the river Natiso , the course of which has changed somewhat since Roman times...

 in dedication to the Virgin Mary on 13 July 1031.