Humphrey IV of Toron
Humphrey IV of Toron( 1166 – 1198) was a leading baron in the Kingdom of Jerusalem.
He inherited the Lordship of Toron from his grandfather, Humphrey II, in 1179.
He was also heir to the Lordship of Oultrejourdan through his mother, Stephanie of Milly.
In 1180, he renounced Toron on his engagement to Isabella, the half- sister of Baldwin IV of Jerusalem.
The king, who had suffered from leprosy, allegedly wanted to prevent Humphrey from uniting two large fiefs.
Humphrey married Isabella in Kerak Castle in autumn 1183.
Saladin, the Ayyubbid sultan of Egypt and Syria, laid siege to Kerak during the wedding, but Baldwin IV and Raymond III of Tripoli relieved the fortress.
Baldwin IV made his young nephew, Baldwin V, his successor before his death, but Baldwin V also died in the summer of 1186.
The barons, who did not want to acknowledge the right of Baldwin V's mother, Sybilla, and her husband, Guy of Lusignan, to inherit the kingdom, decided to proclaim Humphrey and his wife king and queen.
However, Humphrey, who did not want to reign, deserted them and did homage to Sybilla and Guy.
He was captured in 1187 at the Battle of Hattin, where Saladin imposed a crushing defeat on the united army of the Kingdom of Jerusalem.
His mother offered the surrender of the fortresses of Oultrejordain to Saladin in exchange for Humphrey's release.
Although the garrisons of Kerak and Montréal refused to surrender, Saladin set Humphrey free.
Kerak only fell to Saladin's troops in late 1188, Montréal in early 1189.
After Queen Sybilla's death in the autumn of 1190, most barons of the realm( including Isabella's stepfather, Balian of Ibelin) wanted to give Isabella in marriage to Conrad of Montferrat, a successful military leader.
The marriage of Humphrey and Isabella was annulled, although they protested the decision.
Humphrey joined the retinue of King Richard I of England during his crusade in 1191 – 1192.
Since Humphrey was fluent in Arabic, he conducted negotiations with Saladin's brother, Al- Adil, on Richard's behalf.
Baldwin IV of Jerusalem
Baldwin IV (1161 – 16 March 1185), called "the Leper",
or The Leper King, reigned as King of Jerusalem from 1174 until his death.
He was the son of Amalric I of Jerusalem and his first wife, Agnes of Courtenay.
Agnes of Courtenay
Agnes of Courtenay (c. 1136 – c. 1184) was Queen of Jerusalem as the wife of King Amalric I of Jerusalem.
She was the daughter of Joscelin II of Courtenay by his wife Beatrice of Saone, and the mother of King Baldwin IV and Queen Sibylla of Jerusalem.
Alix de Montmorency
Alix de Montmorency( died 24 February 1220/ 1221) was a French noblewoman.
Her parents were Bouchard V de Montmorency and Laurette, daughter of Baldwin IV, Count of Hainaut and Alice of Namur.
Sibylla, Queen of Jerusalem
Sibylla (French: "Sibylle", c. 1160–1190) was the Countess of Jaffa and Ascalon from 1176 and Queen of Jerusalem from 1186 to 1190.
She was the eldest daughter of Amalric I of Jerusalem and Agnes of Courtenay, sister of Baldwin IV and half-sister of Isabella I of Jerusalem, and mother of Baldwin V of Jerusalem.
Her grandmother Melisende had provided an example of successful rule by a queen regnant earlier in the century.
Baldwin IV, Count of Hainaut
Baldwin IV( 1108 – 8 November 1171) was count of Hainaut from 1120 to his death.
He was the son of Baldwin III, Count of Hainaut, and Yolande de Wassenberg.
Isabella I of Jerusalem
Isabella I( 1172 – 5 April 1205) was Queen regnant of Jerusalem from 1190 to her death.
She was the daughter of Amalric I of Jerusalem and his second wife Maria Comnena.
Her half- brother, Baldwin IV of Jerusalem, engaged her to Humphrey IV of Toron.
Her mother's second husband, Balian of Ibelin, and his stepfather, Raynald of Châtillon, were influential members of the two baronial parties.
The marriage of Isabella and Humphrey was celebrated in Kerak Castle in autumn 1183.
Saladin, the Ayyubid sultan of Egypt and Syria, laid siege to the fortress during the wedding, but Baldwin IV forced him to lift the siege.
Baldwin IV, who suffered from lepromatous leprosy, had made his nephew( the only son of his sister, Sybilla by her first husband), Baldwin V, his heir and co-ruler, to prevent Sybilla's second husband, Guy of Lusignan, from mounting the throne.
The High Court of Jerusalem stipulated that a committee of Western European rulers was entitled to choose between Sybilla and Isabella to succeed Baldwin V if he died before reaching the age of majority, but Sybilla and Guy of Lusignan were crowned soon after Baldwin V died in 1185.
Guy's opponents tried to play Isabella and her husband off against him, but Humphrey did homage to the royal couple.
Baldwin V, Count of Flanders
Baldwin V of Flanders( c. 1012 – 1 September 1067) was Count of Flanders from 1035 until his death.
He was the son of Baldwin IV, Count of Flanders, who died in 1035.
Alice of Namur
Alice of Namur( died July 1169 at Valenciennes) was the daughter of Godfrey I, Count of Namur and Ermesinde, Countess of Luxembourg and Longwy the daughter of Conrad I of Luxembourg.
Her father married her off to Baldwin IV, Count of Hainault around 1130.
Gislebert of Mons described her as having" a graceful body and a beautiful face".
Her son was the heir of Namur when her brother Henry IV of Luxembourg died in 1196.
Her children with Baldwin IV of Hainaut were:
She was buried inside Saint Waltrude Collegiate Church.
Benedict I of Jerusalem
Patriarch Benedict of Jerusalem, also Benediktos I of Jerusalem, born Vasileios Papadopoulos (1892 – December 10, 1980) was the Patriarch of Jerusalem of the Greek Orthodox Church of Jerusalem from 1957 to 1980.

Question: Who is the maternal grandfather of Baldwin Iv Of Jerusalem?
Answer: Joscelin II