HMS Duncan has arrived back at Portsmouth Naval Base today after six months in the Mediterranean, Aegean and Black Sea.
The Type-45 frigate was in command of a NATO task force of ships during the deployment.
Duncan's crew of 200 plus multi-national staff left the UK in January to take charge of NATO’s Standing Maritime Group 2.
The group was made up of a selection of frigates, destroyers and patrol ships from across the alliance's navies.
Defence Secretary Gavin Williamson said:
"HMS Duncan and her crew have demonstrated why the Royal Navy is revered all over the world for its leadership, professionalism, and skill."
Commanding Officer, Commander Eleanor Stack said: "HMS Duncan has provided an ultra-modern and uniquely-capable platform from which the UK’s command of the NATO’s Standing Maritime Group Two has been conducted successfully.
"I am incredibly proud of my ship’s company in everything they have achieved over the last 12 months in conducting operations from Odessa to Haifa and Georgia to Tartus."
Next year, HMS Duncan will be back leading the NATO mission in the Mediterranean.