The Prime Minister has paid tribute to the work of the Armed Forces in her annual Christmas message to the military.
Mrs May said 2018 had allowed the military “to demonstrate why you are the finest in the world".
In particular, she highlighted the Armed Forces’ response to the Russian Novichok attack in Wiltshire and those serving overseas away from their loved ones.
"From playing a vital role in cleaning up after a sickening nerve agent attack on the streets of Salisbury, protecting our waters and our skies from Russian intrusion and strengthening our allies in Eastern Europe, striking at terrorism as part of the Global Coalition against Daesh, and along with our US and French allies - sending a message to the Assad regime that we will not stand by while chemical weapons are used, as they were in April on families, including young children," she said.
"Time and again, you have stood up to aggression and those who flout the rules-based international order.
"You should be incredibly proud of all that you do, just as the whole country is proud of you."
She continued: "Now as we approach the New Year, there will be new challenges ahead.
"But I know you will continue to meet them in the same way that you have always done. With courage, determination, resilience, ingenuity.
"Qualities that are as vital now as they have ever been."