question: Who is the father of Soběslav I, Duke Of Bohemia?
context: [["Sob\u011bslav I, Duke of Bohemia", ["Sob\u011bslav I (also \"Sobeslaus\"; c.1075 \u2013 14 February 1140) was Duke of Bohemia from 1125 until his death.", "He was a member of the P\u0159emyslid dynasty, the youngest son of Vratislaus II (d. 1092), by his third wife \u015awi\u0119tos\u0142awa of Poland."]], ["Wenceslaus II, Duke of Bohemia", ["Wenceslaus II( 1137 \u2013 after 1192) was the son of Sob\u011bslav I and brother of Sob\u011bslav II.", "He was the duke of Bohemia following Conrad II in 1191.", "He was the duke of Olomouc and Brno, but was deposed by Duke Frederick in 1179 and exiled.", "He returned from exile after thirteen years on Conrad's death.", "Wenceslaus was deposed after a reign of three months by Frederick's half- brother Ottokar.", "He tried to flee to the Emperor Henry VI, but was captured by the margrave of Lusatia, who imprisoned him until his death."]], ["Ludmila (wife of Mieszko I Tanglefoot)", ["Ludmila( d. October 20 after 1210) was the wife of Mieszko I Tanglefoot.", "Her origins are disputed.", "Mieszko I Tanglefoot married Ludmila between 1170- 1178.", "Given her name, scientists think that Ludmila came from Bohemia, a member of the P\u0159emyslid dynasty, since this was one of the only families to have women in it called Ludmila.", "However researchers have different opinions.", "It was suggested that she was daughter of Otto III, Duke of Olomouc and his wife Durantia, probably the daughter of Mstislav I of Kiev by his second wife Liubava Dmitrievna.", "There was also a minority hypothesis that Ludmila was daughter of Sob\u011bslav I, Duke of Bohemia, Conrad II, Duke of Znojmo or Vladimir, Duke of Olomouc.", "Ludmilla contributed to the foundation of the Norbertine monastery in Rybnik, who was later transferred to Czarnow\u0105sy.", "Mieszko and Ludmila had the following children:"]], ["Margaret of Bohemia, Duchess of Bavaria", ["Margaret of Bohemia( 1313\u20131341) was the daughter of King John of Bohemia by his first wife Elisabeth of Bohemia( 1292\u20131330)."]], ["Anne of Bohemia (1290\u20131313)", ["Anne of Bohemia( 1290 \u20131313) was the eldest surviving daughter of Wenceslaus II of Bohemia and Poland and his first wife Judith of Habsburg.", "Her siblings included Elisabeth of Bohemia and Wenceslaus III of Bohemia."]], ["Morris Harvey", ["Morris Harvey( 1877\u2013 1944) was a British actor and writer.", "A renowned character actor, he also wrote for the stage, including material for Broadway revues, in which he also appeared.", "He was the stepfather of film director Anthony Harvey."]], ["Jerrold Wexler", ["Jerrold Wexler( June 27, 1924 \u2013 November 10, 1992) was a noted American businessman and film producer.", "He was the brother of cinematographer Haskell Wexler and the stepfather of actress Daryl Hannah."]], ["\u015awi\u0119tos\u0142awa of Poland", ["\u015awi\u0119tos\u0142awa of Poland ((c. 1046-1048 \u2013 1 September 1126)) was the third wife of Duke (later King)", "Vratislaus II of Bohemia and the first Queen of Bohemia as of 1085."]], ["Adelaide of Hungary (d. 1140)", ["Adelaide of Bohemia( 1105/07 \u2013 15 September 1140) was a daughter of Prince \u00c1lmos of Hungary and his wife Predslava of Kiev.", "Adelaide's father was a son of King G\u00e9za I of Hungary and was Duke and later King of East Slavonia.", "Adelaide married Sob\u011bslav I, Duke of Bohemia.", "They had at least five children:"]], ["H\u00e9ctor Barrantes", ["H\u00e9ctor Barrantes Sansoni( 1939\u20131990) was an Argentine polo player.", "He was the stepfather of Sarah, Duchess of York."]]]
supporting_facts: [["Sob\u011bslav I, Duke of Bohemia", 1], ["\u015awi\u0119tos\u0142awa of Poland", 1]]
evidences: [["Sob\u011bslav I, Duke of Bohemia", "mother", "\u015awi\u0119tos\u0142awa of Poland"], ["\u015awi\u0119tos\u0142awa of Poland", "spouse", "Vratislaus II of Bohemia"]]
answer: Vratislaus II of Bohemia