As the invasion of Ukraine began last February, Charlotte Thornycroft was organizing events for the Queen’s Platinum Jubilee celebrations at Windsor Castle later that year. A former assistant to Saudi prince Khalid bin Abdullah, the late racehorse owner of Juddmonte Farms, she remembers being horrified not only by the plight of the Ukrainian people but by that of the country’s abandoned horses. Despite having no experience working in a war zone, Thornycroft felt compelled to help. So, for the last year, she has been running a horse shelter in Rzeszow, Poland, that has already provided refuge for more than 300 horses from Ukraine.

Initially it was a temporary stabling structure that housed the horses before they were transported to different parts of Europe. However, due to the sheer number of animals arriving, along with the stringent regulations on transporting animals across Europe, the facility was soon transformed into a permanent shelter.

Thornycroft vividly remembers 15 horses arriving on her third day of work. Some of them were accompanied by their owners and, in a few cases, small children, who were seeking refuge. While the children were eventually found homes, the horses had nowhere else to go, and soon Thornycroft found herself solely responsible for the well-being of dozens of horses.

Before the war, there were thought to be around 100,000 horses in Ukraine, including prize-winning racers, breeding stock, and family pets. Today the number is unknown. Unlike dogs and cats, who are natural scavengers and hunters, domesticated horses require humans to keep them alive, especially in a freezing war zone. Many were simply set loose to fend for themselves when their owners were forced to flee the country.

Russian attacks killed some, others died from starvation or injury, and there are suspicions that a significant number of horses were stolen for the meat trade. What is known for certain is that tens of thousands of horses left in Ukraine do not have enough food to survive much longer.

Living off her savings, but with assistance from various British charities under the umbrella group British Equestrians for Ukraine, Thornycroft and five volunteers drive horse trailers into Ukraine packed with supplies for the humanitarian effort—everything from essential medicines to “luxuries” such as shampoo and toothpaste. Once the supplies are delivered to the areas that need them, the drivers then collect as many abandoned horses as they can.

They initially found the horses via requests for help on Facebook groups, but now the Ukraine Equestrian Charity Federation gives Thornycroft’s details to anyone needing help. Once found, the horses are either relocated to two safe havens created within Ukraine or taken directly to Poland.

Russian attacks killed some, others died from starvation or injury, and there are suspicions that a significant number of horses were stolen for the meat trade.

Exactly when Thornycroft sets off on a mission depends on the air raids. Then there is the added danger of navigating her way to the destination. Both Russians and Ukrainians are scrambling G.P.S. signals, so most phone apps are unreliable, detailed paper maps of the region are hard to get hold of, and almost all the signposts in Ukraine have been covered or removed to disorient the invading Russian forces.

Thornycroft recalls driving in the dark at two in the morning—no lights are allowed in Ukraine after eight p.m. and car lights must be dimmed—and being waved through a checkpoint by a Ukrainian soldier. A hundred yards later she realized the bridge she was driving toward had been totally destroyed: “The soldier … had said nothing.”

Thornycroft describes another incident where one driver was caught by Russian troops, dragged out of his trailer, and beaten. The horses were let loose, the engine wires were cut, and all his documents, including his passport, were stolen. Even then, it could have been much worse. The trailers are scarred with bullet and shrapnel marks.

When not dealing with devastated roads or uncaring soldiers, Thornycroft battles red tape. There are huge bureaucratic hurdles involved in moving horses from a non-E.U. country to an E.U. one. They require microchips inserted beneath the skin that carry a unique number, animal passports, and blood tests, which can cost thousands of dollars per horse.

Similarly, any animal-welfare donations sent to her in Poland from other parts of Europe must be painstakingly sorted beforehand. E.U. regulations say the same vehicle cannot carry food and clothes. It is an excruciating process knowing that supplies are being delayed while the items are sorted.

Sometimes E.U. law prevents them from taking everything they are sent. “The only thing I threw away, and which made me cry, was a whole lorry load of out-of-date vet meds,” says Thornycroft. “We had sick and malnourished horses, some with shrapnel wounds, but we couldn’t use [the meds] because the vets [in Ukraine] would lose their license if caught.”

There has been pressure from other European equestrian organizations to try to give the horses refugee status to reduce the suffocating regulation. But these efforts are hampered by concerns that if border laws are relaxed—as they have been in neighboring Romania—thousands of horses will be shipped across the border for meat.

Thornycroft has gone well beyond rescuing horses. She has transported dozens of women and girls from the Mariupol and Odessa regions over the border to have abortions after they were raped by Russian and, she says, Ukrainian soldiers. “One of the women said she couldn’t go back to Ukraine because she had been raped and her husband was a soldier so he would not accept her,” recalls Thornycroft. The medication she is most frequently asked to bring with her on her trips into Ukraine are pills to end pregnancies.

But in the lives of the people she transports, Thornycroft has found a dogged determination to carry on. She recalls a 16-year-old girl who came with her horse to the shelter, but immediately returned to Ukraine in order to finish her education once she knew her beloved horse was safe. “That is the sort of decision they are making on a daily basis,” she says.

Thornycroft is now helping to set up a rehabilitation center in the north of Ukraine using horses to help soldiers and civilians with PTSD. Equine-assisted psychotherapy is known to be a useful treatment to help this condition. Last Thursday, she was presented with an award for her exceptional heroism by Princess Anne at the National Equine Forum.

When she first traveled to Ukraine, Thornycroft thought it would just be a case of rounding up horses and bringing them across the border. But “the reality is that every horse has a family attached to it, whether they are dead or alive.” Like the many thousands of people who have escaped the war-torn country, no one knows if, or when, they will be re-united.

Eleanore Kelly is a former elite equestrian athlete. She is now a journalist for newspapers and television, including the BBC and Reuters