One of the ten Companions promised Jannat by the Prophet salla Llahu ‘alayhi wa sallam and amongst the forerunners of the Muhajirin.
Talhah, the son of ‘Ubaidullah, the son of ‘Uthman, the son of ‘Amr, the son of ‘Amir, the son of Ka’b, the son of Sa’d, the son of Taym, the son of Murrah, the son of Ka’b.
His genealogy meets with that of the Prophet salla Llahu ‘alayhi wa sallam at Murrah, and meets with that of Abu Bakr al Siddiq radiya Llahu ‘anhu at Ka’b ibn Sa’d.
His mother is al Sa’bah al Hadrami, the daughter of ‘Abdullah, the son of ‘Imad, the son of Akbar, the son of Rabi’ah, the son of Malik, the son of ‘Uwayf al Hadrami.
She is the sister of ‘Ala’ al Hadrami the eminent Sahabi of the Prophet salla Llahu ‘alayhi wa sallam, who was Mustajab al Da’wah.
The son of Sayyidina Hassan ibn ‘Ali radiya Llahu ‘anhu—the grandson of the Prophet salla Llahu ‘alayhi wa sallam—was named Talhah.
This has been recorded by a number of historians and genealogists, amongst them:
Ibn Qutaybah writes:
The children of Hassan: Hassan—whose mother was Khawlah bint Manzur ibn Zaban al Fazariyyah; Zaid and Umm Hassan—whose mother was Umm ‘Aqabah ibn Mas’ud al Badri; ‘Umar—whose mother was Thaqafiyyah; Hussain al Athram—whose mother was an Umm Walad; Talhah—whose mother was Umm Ishaq bint Talhah ibn ‘Ubaidullah…
Mus’ab al Zubairi says:
Talhah ibn Hassan: his mother was Umm Ishaq bint Talhah ibn ‘Ubaidullah al Taymi. Talhah ibn Hassan is the half-brother (Uterine brother—both sharing the same mother) of Fatimah bint Hussain ibn ‘Ali ibn Abi Talib and Aminah bint ‘Abdullah ibn Muhammad ibn ‘Abdul Rahman ibn Abi Bakr al Siddiq.
One cannot help but marvel at this ancestry, by Allah, it is a beautiful example of kinship and joining family ties.
Sayyidina Talhah ibn ‘Ubaidullah radiya Llahu ‘anhu was the co-brother-in-law to the Prophet salla Llahu ‘alayhi wa sallam through four marriages. Sayyidina Talhah radiya Llahu ‘anhu was married to four sisters of four of the wives of the Prophet salla Llahu ‘alayhi wa sallam:
Ibn Tiqtaqa writes:
Hassan al Muthallath had five children: Muhammad, ‘Abdullah, ‘Abbas, Talhah, and ‘Ali.
 Al Sa’bah al Hadrami embraced Islam and was blessed with being amongst the Companions of the Prophet salla Llahu ‘alayhi wa sallam. Al Isabah pg. 1718 #12069; one may also refer to the biography of Talhah radiya Llahu ‘anhu in al Isabah, pg. 641, #4428; al Isti’ab, #1287; Usd al Ghabah, #2672; Asma al Sahabah of Ibn Hazm, pg. 95; Talqih Fuhum Ahl al Athar of Ibn al Jawzi, pg. 366.
 One whose supplications are readily accepted.
 Co-brother-in-law: One married to the sister of one’s wife.