Guido de Summa was an Italian Cardinal

Cardinal (Catholicism)

A cardinal is a senior ecclesiastical official, usually an ordained bishop, and ecclesiastical prince of the Catholic Church. They are collectively known as the College of Cardinals, which as a body elects a new pope. The duties of the cardinals include attending the meetings of the College and...

.

He was born in Milan

Milan

Milan is the second-largest city in Italy and the capital city of the region of Lombardy and of the province of Milan. The city proper has a population of about 1.3 million, while its urban area, roughly coinciding with its administrative province and the bordering Province of Monza and Brianza ,...

. Pope Celestine II

Pope Celestine II

Pope Celestine II , born Guido di Castello, was pope from 1143 to 1144.-Early life:Guido di Castello, possibly the son of a local noble, Niccolo di Castello, was born either in Città di Castello, situated in Paterna Santa Felicita upon the Apennines, or at Macerata in the March of Ancona.Guido had...

 created him Cardinal-Priest of S. Lorenzo in Damaso in the consistory celebrated on December 17, 1143. He subscribed the papal bulls between December 28, 1143 and April 14, 1150 and participated in the papal election, 1144

Papal election, 1144

The papal election of 1144 followed the death of Pope Celestine II and resulted in the election of Pope Lucius II.-Election Lucius II:Pope Celestine II died on 8 March 1144 at Rome, after pontificate of only five months. The election of his successor took place in the shadow of this municipal...

 and papal election, 1145

Papal election, 1145

The papal election of 1145 followed the death of Pope Lucius II and resulted in the election of Pope Eugene III, the first pope of the Order of Cistercians.-Election of Eugene III:...

. On September 23, 1149 Eugenius III

Pope Eugene III

Pope Blessed Eugene III , born Bernardo da Pisa, was Pope from 1145 to 1153. He was the first Cistercian to become Pope.-Early life:...

 consecrated him Bishop of Ostia

Bishop of Ostia

The Bishop of Ostia is the head of the Suburbicarian Diocese of Ostia, one of the seven suburbicarian sees of Rome. The position is now attached to the post of Dean of the College of Cardinals, as it has been since 1150, with the actual governance of the diocese entrusted to the Vicar General of...

. For many years he acted as papal legate in Lombardy. He is attested for the last time in the document issued in Ferentino on May 10, 1151.