Aaron's sons
Nadab, Abihu, Eleazar, and Ithamar were consecrated as priests. After Nadab and Abihu died for offering unauthorized fire, Eleazar and Ithamar continued the priesthood. Numbers assigns Ithamar oversight of the Gershonite and Merarite work associated with transporting and maintaining the tabernacle. Later priestly lines, including Eli's house, were associated with Ithamar.