Two British nationals were killed while attempting a “humanitarian evacuation” from the Ukrainian town of Soledar, according to a statement from the family.
Chris Parry and his colleague Andrew Bagshaw were killed in the eastern city.
A statement released on behalf of Mr Parry’s family said: “His selfless determination to help the old, young and disadvantaged there has made us and his large family extremely proud.
“We never imagined saying goodbye to Chris when he had such a full life ahead of him. He was a caring son, a fantastic brother, a best friend to so many and a loving partner to Olga.
“He found himself drawn to Ukraine in March in its darkest hour at the start of the Russian invasion and helped those most in need, saving over 400 lives and many abandoned animals.
“It’s impossible to say how much he will be missed, but he will forever be in our hearts.”