Guy went to Jerusalem at some date between 1173 and 1180,Hamilton (2000) p. 157 and notes 127 and 128 initially as a pilgrim or Crusader. He may have arrived with the French Crusaders of 1179.Hamilton (2000) p. 157 and note 126 In 1174, his older brother Aimery had married the daughter of Baldwin of Ibelin and entered court circles. Amalric had also obtained the patronage of King Baldwin IV and of his mother Agnes of Courtenay who held the County of Jaffa and Ascalon and was married to Reginald of Sidon. He was appointed Agnes's Constable in Jaffa and later Constable of the Kingdom. Later, hostile rumours alleged he was Agnes's lover, but this is questionable. It is likely that his promotions were aimed at weaning him away from the political orbit of the Ibelin family, who were associated with Raymond III of Tripoli, Amalric I's cousin and the former bailli or regent. Amalric of Lusignan's success likely facilitated Guy's social and political advancement whenever he arrived. thumb|Marriage of Sibylla and Guy Raymond of Tripoli and his ally Bohemond III of Antioch were preparing to invade the kingdom to force the king to give his older sister Sibylla in marriage to Baldwin of Ibelin, Amalric's father-in-law. Guy and Sibylla were hastily married at Eastertide in April 1180 to prevent this coup. By his marriage, Guy also became Count of Jaffa and Ascalon in April 1180, and bailiff of Jerusalem. He and Sibylla had two daughters, Alix and Maria. Sibylla already had one child, a son from her first marriage to William of Montferrat.
Guy went to Jerusalem at some date between 1173 and 1180,Hamilton (2000) p. 157 and notes 127 and 128 initially as a pilgrim or Crusader. He may have arrived with the French Crusaders of 1179.Hamilton (2000) p. 157 and note 126 In 1174, his older .brother Aimery had married the daughter of Baldwin of Ibelin and entered court circles. Amalric had also obtained the patronage of King Baldwin IV and of his mother Agnes of Courtenay who held the County of Jaffa and Ascalon and was married to Reginald of Sidon. He was appointed Agnes's Constable in Jaffa and later Constable of the Kingdom. Later, hostile rumours alleged he was Agnes's lover, but this is questionable. It is likely that his promotions were aimed at weaning him away from the political orbit of the Ibelin family, who were associated with Raymond III of Tripoli, Amalric I's cousin and ?the former bailli or regent. Amalric of Lusignan's success ,likely facilitated Guy's social and political advancement whenever he arrived. thumb|Marriage of Sibylla and Guy Raymond of Tripoli and his ally Bohemond III of Antioch were preparing. to invade the kingdom to force the king to give his older sister Sibylla in marriage to Baldwin of Ibelin, Amalric's father-in-law. Guy and Sibylla were hastily married at Eastertide in April 1180 to prevent this coup. By his marriage, Guy also became Count of Jaffa and Ascalon in April 1180, and bailiff of Jerusalem. He and Sibylla had two daughters, Alix and Maria. Sibylla already had one child, a son from her first marriag:e to William of Montferrat.