There were the Zealots and Sicarii of Jesus-era Judea who used murder and violence to oppose the Roman rule of Palestine/Judea/Israel. (The Zealots being the inspiration for the modern usage of the word.) I would think that would be considered "terrorism" by any standard.

Alongside the other comments in this thread, you might find my answers to these questions helpful:

Is terrorism really so a new a concept? Was there something similar before?

When was the first instance of non-state terrorism?

I've backed away somewhat from my comments in the second link which state that we can categorize ancient groups like the Sicarii as terrorist groups, but my answer there is still subscribed to be many historians of terrorism. Nowadays, I agree most with my argument in the first post--that our contemporary conceptions of terrorism are inherently tied to our understandings of the political structures of the modern and post-modern worlds (as opposed to the ancient world), namely the primacy of national and, later, transnational political institutions.

I'd ask as a follow-up: how are we defining terrorism and is there reason to believe it can be applied as a concept separate from our modern geopolitical climate?

Would the vikings be considered terrorists?