Birth: Exodus 6:23; 1 Chronicles 6:3
Death: (not stated)
Father: Aaron
Mother: Elisheba
Uncle: Moses
Brothers: Nadab, Abihu, and Eleazar
Post-Flood lineage: Abraham > Isaac > Jacob > Levi > Kohath > Amram > Aaron > Ithamar
Ithamar came from the line of Jacob via Levi who were designated as Israel's priests - 1 Chronicles 6:1-3
One of four brothers, Ithamar served as an Israelite priest since he was a Levite -
Exodus 28:1. Considering his father was Moses' brother, Ithamar oversaw the
"materials used for the tabernacle" as stated in Exodus 48:21.
His position over other priests was stated again in Numbers 4:28,33 and
7:8.
Other mentions: Numbers 3:2 and 26:60; Leviticus 10:6,12 and 16.
Two of his brothers, Nadab and Abihu died by fire "in the Desert of Sinai", according to Numbers 3:4. They were also mentioned again in 1 Chronicles 24:2.
1 Chronicles 24:1-6:
1. These were the divisions of the sons of Aaron: The sons of Aaron were Nadab, Abihu, Eleazar and Ithamar.
2. But Nadab and Abihu died before their father did, and they had no sons; so Eleazar and Ithamar served as the priests.
3. With the help of Zadok a descendant of Eleazar and Ahimelech a descendant of Ithamar, David separated them into divisions for their appointed order of ministering.
4. A larger number of leaders were found among Eleazar's descendants than among Ithamar's, and they were divided accordingly: sixteen heads of families from Eleazar's descendants and eight heads of families from Ithamar's descendants.
5. They divided them impartially by drawing lots, for there were officials of the sanctuary and officials of God among the descendants of both Eleazar and Ithamar.
6. The scribe Shemaiah son of Nethanel, a Levite, recorded their names in the presence of the king and of the officials: Zadok the priest, Ahimelech son of Abiathar and the heads of families of the priests and of the Levites--one family being taken from Eleazar and then one from Ithamar.
Someone named Daniel is listed among the "list of the family heads returning with Ezra" in Ezra 8:2; but, it's doubtful that it is the prophet Daniel.