The Royal Navy vessels brought military vehicles and equipment to resupply the UK-led Nato battlegroup in Estonia, an area of ‘geographical interest’ in the conflict.
They also conducted navigation patrols and exercises alongside ships and aircraft from six Joint Expeditionary Force (JEF) nations.
The Baltic Sea is of vital strategic importance in ensuring stability and freedom of navigation in the area especially after the war broke out.
It comes as the number UK personnel in Poland and Estonia was doubled to boost Nato deployment on the eastern flank of the conflict zone.
Type 23s HMS Northumberland and HMS Richmond, both based at Devonport, worked with warships from Denmark, Sweden, Estonia, Latvia and Lithuania to deliver Nato supplies.
The UK’s new RAF Poseidon P8A submarine hunter aircraft also practised working with the ships to spot enemy vessels.
Major General Jim Morris, the commander of the UK Standing Joint Force HQ (SJFHQ) which leads the JEF, said: ‘Activities such as these in the Baltic Sea are routine business for us and our JEF partners, in one of our principal areas of geographical interest.
‘Given the current level of aggression being displayed by Russia, there has never been a more important time to ensure that freedom of navigation is maintained in the Baltic Sea.”
The commanding officer of HMS Richmond, Chris L’Amie said: ‘Our short but intense period in the Baltic Sea has seen Richmond integrate with a number of JEF nations and I have been highly impressed with the adaptability and professionalism of the ship’s company.’