Leonid Onyshchenko, a gruff-voiced 63-year-old Ukrainian soldier with a thick moustache, has spent many a Christmas away from his family, but hearing his little grandson Petro’s voice over the phone from far away is as hard as ever.

Onyshchchenko joined the territorial defence force after Moscow’s February invasion, and has volunteered to support Ukraine’s army in the fight against Russian-backed separatists in the country’s east since 2014.

While he is stationed in the Donetsk region which has seen some of the heaviest battles, his daughter Maryna and her husband Vitalii were celebrating Christmas at home in Kharkiv, Ukraine’s second biggest city, frequently under Russian attack.

Holding her three-monthold son Yaroslav with one hand, Maryna took a Christmas cake out of the oven with the other.

Vitalii helped two other sons, Petro and Tais, get dressed before the festive Christmas dinner.

In the past, Ukrainian Christians mostly celebrated Christmas in early January. This year the holiday is celebrated by many on December 25, as Ukraine’s main Orthodox Church has broken with Moscow and turned its face towards the West.

War has scattered the family. Maryna’s two older daughters and her mother fled to the western city of Lviv. As the family gathers around the table, Maryna calls her father to wish him merry Christmas. Little Petro takes the phone.

“I just want to tell you that Christmas is coming and Santa Claus is coming. I was a good boy,” the boy says.

Speaking is a comfort, says Onyshchenko, known among fellow soldiers under the nomde-guerre ‘Deer’.

“On one hand, we will see and hear each other. But on the other hand, we are hundreds kilometers apart. I cannot compare it with anything. But nevertheless, we are one big family.”