Seraiah (called "Azariah" in 1 Chronicles 9:11) designates the high priestly family of this time, as in Nehemiah 10:2; Nehemiah 12:1, Nehemiah 12:12. The "Seraiah" who gave name to it was probably the high priest taken prisoner by Nebu-zaradan, and put to death (—2 Kings 25:18-21).
The son of Hilkiah. Really the grandson (Ezra 7:1). The son of Meshullam. Or "Shallum" (ibid. Nehemiah 12:2). The ruler of the house of God. i.e. the high priest; or, rather, the family which furnished the high priests at this time.
The actual high priest was Eliashib, the son of Joiakim, and grandson of Jeshua (see Nehemiah 12:10; Nehemiah 13:4).