A politically-motivated Jewish party in the first century, supporters of the Herodian dynasty and accommodationist toward Roman rule. They appear three times in the Gospels — always teaming up with the Pharisees against Jesus (Mark 3:6, 12:13; Matthew 22:16) — a striking alliance of opposites, because the Pharisees opposed Roman collaboration while the Herodians embraced it. What unified them was mutual hostility to Jesus. Not a theological sect so much as a political faction, the Herodians likely favored a secular, pragmatic Jewish identity tolerant of Hellenism and Roman patronage so long as Herodian rule persisted.
The Herodians' most famous appearance is the "render unto Caesar" question (Matthew 22:15-22). The Pharisees — who would normally have nothing to do with Herodian collaborators — joined them in a trap designed to leave Jesus no safe exit. If Jesus said "yes, pay taxes," the Pharisees would denounce Him to the people as a Roman sympathizer. If He said "no, don't pay," the Herodians would denounce Him to Rome as a seditionist. Jesus' reply — "Render to Caesar the things that are Caesar's, and to God the things that are God's" — split the horns of the dilemma and became the foundational text of Christian political theology: there are two orders of loyalty, distinct but related, and the higher (God) outranks the lower (Caesar) without obliterating it. The Herodians remind us that political expediency often outranks principle in fallen politics — strange bedfellows unite when a common enemy emerges. Today's equivalent: any coalition whose only glue is shared opposition to Christ.