The first British volunteer killed in action against the Islamic State is being mourned by those who fought alongside him. One fellow volunteer told VICE News what it was like to fight alongside him — and talked about his struggles with his former employer, the Royal Marine Commandos.

Konstandinos Erik Scurfield, known as Kosta to his fellow fighters, is just the second foreign volunteer to die fighting alongside the People's Protection Units (YPG), a predominantly Kurdish militia.

"He was hands down one of the greatest human beings I have ever met," fellow volunteer John Foxx told VICE News. "From beginning to end he was 100 percent about helping everyone else. No matter what the issue was or who you were he would try to help you however he could."

The two men were part of a team of foreign fighters nicknamed the Chappies.

"We are all torn up. He was always raising the morale of our team. He was always maintaining his fitness and motivating every one of us," Foxx said.

"He would always volunteer to be on the ambush team, spend the night on the berm [defensive fortification] or go on any assault. We usually did not need volunteers but Kosta was always the one who would volunteer for any job that might inconvenience somebody else.

"When I broke my arm in Syria, Kosta, Matt, and Jordan had to cover my shifts on the ambush teams because I couldn't shoulder my rifle with my cast on.

"When some guys would be tasked out on other missions and we needed somebody to fill in for them on the ambush team that night, even though Kosta did it the night before, or multiple nights in a row, he would still volunteer."

Photo via Konstandinos Erik Scurfield/Facebook

Foxx, an American, said Kosta arrived in Syria at the beginning of December.

"He was tired of seeing what ISIS [the Islamic State] was doing to people out here. His first intention was to go to Kobane [the besieged Kurdish enclave in Northern Syria] and be a medic but then he became aware of the official route to join the YPG."

Foxx was critical of Kosta's former employer, the Royal Marines, who, he says, opposed Kosta's decision to fight in Syria.

"His family did not know he came to Syria and he tried very hard to keep that fact a secret. The Royal Marines were upset that he chose to fight ISIS rather than staying in the Royal Marine Corps so they called his family and told them he was over in Syria. He was very, very upset over that. They had no business making his parents worry like that," Foxx claimed.

A spokesperson for the Ministry of Defence declined to comment, or to confirm that Kosta had been a Royal Marine.

VICE News could not confirm the circumstances under which Kosta left the Marines.

There are thought to be fewer than 100 foreign volunteers currently fighting alongside the YPG, but there are plans to accommodate a surge of interest, according to Facebook posts by existing volunteers.

A 28-year-old Australian, Ashley Johnston, became the first foreign volunteer to be killed in combat against Islamic State on February 23.

Another foreign volunteer, Dean Parker, who has recently returned to the United States, said that almost all the volunteers had made the journey aware of the extremely difficult and dangerous conditions which they were entering.

"Just our presence there gives such a moral boost to the young YPG and YPJ fighters, that's a very big part of it," Parker said.

The YPJ, or Women's Protection Units, are an all-female force that fights alongside the YPG.

Photo via Konstandinos Erik Scurfield/Facebook

The BBC and others have reported that Kosta died in Qamishli, a city in northeastern Syria near the border with Turkey. Kurdish forces recently seized the city from Islamic State.

On September 25, 2014, before he travelled to Syria, Kosta posted a quotation to his Facebook profile from the German anti-Nazi activist Sophie Scholl who was executed in 1943.

"How can we expect righteousness to prevail when there is hardly anyone willing to give himself up individually to a righteous cause," the quotation read. "Such a fine, sunny day, and I have to go, but what does my death matter, if through us, thousands of people are awakened and stirred to action?"