Question: Who is the paternal grandfather of Constance Of Sicily, Dogaressa Of Venice?

Knowledge 1: Constance of Sicily, Dogaressa of Venice
Constance of Sicily (floruit 1220), was a Sicilian Princess and the Dogaressa of Venice by marriage to the Doge Pietro Ziani (r. 1205–1229).She was the daughter of Tancred, King of Sicily, and Sibylla of Acerra.Her father died in 1194, and her brother was deposed later that same year, by Henry VI, Holy Roman Emperor, who also captured Constance, her mother and her two sisters.She married the Doge Pietro Ziani in 1213, after the death of his former dogaressa Maria Baseggio.The marriage was arranged on the suggestion of the doge as a confirmation and reneval of the Treaty of Venice between Sicily and Venice, which had been forged by the father of Pietro Ziani, doge Sebastiano Ziani, and William II of Sicily, the predecessor of Constance's father.This was the first time a Doge of Venice had married a Princess since Theodora Anna Doukaina Selvo in the 11th-century.She was described as beautiful and dignified, "a woman of conspicuous ability and ambition" and well suited to play the part of a princely consort of the ambitious Doge.She is described by Palazzi:She was said to respond to all complaints about herself or her spouse with the words: "I have nothing to do with you!"The marriage between Constance and Ziani are described as a happy one.Pietro Ziani had only one child, a son, from his first marriage, who died as a child, but his second marriage produced Marco, Marchesina and Maria.There are three versions of her death.One version claim that she died during the earthquake of 1220.A second version that she died suddenly in 1228, and that the Doge took it so badly that he abdicated and died soon after.The third version claim that she was still alive when Pietro Ziani left his office in 1229 and that they lived a peaceful life for several years in retirement in their palace on Santa Giustina.In 1242, her sister Valdrada of Sicily was to become dogaressa by marriage to her husband's successor. [SEP] Knowledge 2: Tancred, King of Sicily
Tancred (1138 – 20 February 1194) was King of Sicily from 1189 to 1194.He was born in Lecce an illegitimate son of Roger III, Duke of Apulia (the eldest son of King Roger II) by his mistress Emma, a daughter of Achard II, Count of Lecce.He inherited the title "Count of Lecce" from his grandfather and is consequently often referred to as "Tancred of Lecce".Due to his short stature and unhandsome visage, he was mocked by his critics as "The Monkey King".
Knowledge 1: Constance of Sicily, Dogaressa of Venice
Constance of Sicily (floruit 1220), was a Sicilian Princess and the Dogaressa of Venice by marriage to the Doge Pietro Ziani (r. 1205–1229).She was the daughter of Tancred, King of Sicily, and Sibylla of Acerra.Her father died in 1194, and her brother was deposed later that same year, by Henry VI, Holy Roman Emperor, who also captured Constance, her mother and her two sisters.She married the Doge Pietro Ziani in 1213, after the death of his former dogaressa Maria Baseggio.The marriage was arranged on the suggestion of the doge as a confirmation and reneval of the Treaty of Venice between Sicily and Venice, which had been forged by the father of Pietro Ziani, doge Sebastiano Ziani, and William II of Sicily, the predecessor of Constance's father.This was the first time a Doge of Venice had married a Princess since Theodora Anna Doukaina Selvo in the 11th-century.She was described as beautiful and dignified, "a woman of conspicuous ability and ambition" and well suited to play the part of a princely consort of the ambitious Doge.She is described by Palazzi:She was said to respond to all complaints about herself or her spouse with the words: "I have nothing to do with you!"The marriage between Constance and Ziani are described as a happy one.Pietro Ziani had only one child, a son, from his first marriage, who died as a child, but his second marriage produced Marco, Marchesina and Maria.There are three versions of her death.One version claim that she died during the earthquake of 1220.A second version that she died suddenly in 1228, and that the Doge took it so badly that he abdicated and died soon after.The third version claim that she was still alive when Pietro Ziani left his office in 1229 and that they lived a peaceful life for several years in retirement in their palace on Santa Giustina.In 1242, her sister Valdrada of Sicily was to become dogaressa by marriage to her husband's successor. [SEP] Knowledge 2: Morosina Morosini
Morosina Morosini-Grimani (1545 - January 21, 1614), was a Venetian patrician.She was the Dogaressa of Venice from 1595 to 1606.
Knowledge 1: Tancred, King of Sicily
Tancred (1138 – 20 February 1194) was King of Sicily from 1189 to 1194.He was born in Lecce an illegitimate son of Roger III, Duke of Apulia (the eldest son of King Roger II) by his mistress Emma, a daughter of Achard II, Count of Lecce.He inherited the title "Count of Lecce" from his grandfather and is consequently often referred to as "Tancred of Lecce".Due to his short stature and unhandsome visage, he was mocked by his critics as "The Monkey King". [SEP] Knowledge 2: Morosina Morosini
Morosina Morosini-Grimani (1545 - January 21, 1614), was a Venetian patrician.She was the Dogaressa of Venice from 1595 to 1606.

Answer: Roger III, Duke of Apulia