I’ll never forget some of the people and things that I saw in 2015, as I followed the story of Syrian refugees from the country’s border down through Turkey and across the Aegean Sea to the Greek Islands.

To say that the plight of these refugees was one of the defining stories of the year would be an understatement.

How many of us will ever forget that image of Alan Kurdi the three-year-old Syrian boy whose body was washed up on a beach near the Turkish port city of Bodrum.

Alan died along with his five-year-old brother and his mother while trying to reach the Greek island of Kos.

That photograph of Alan’s body, his tiny legs dangling from the arms of the Turkish policeman who carried him from the beach went on to resonate around the world causing outrage.

That outrage however proved to be comparatively short lived, as the refugees continued to come reaching a Europe where the response was a mixture of confusion, fear, hostility and hospitality.

For the simple indisputable fact is that long after that picture of Alan Kurdi indelibly etched itself into the world’s collective psyche, refugee children like him continue to die while making the hazardous journey with their families across the Aegean and Mediterranean Seas. They continue to do so even as I write this.

Two of those who died, a little boy and girl, were the children of a man called Ali Chadan who I was to meet on the Greek island of Kos last month.

For Ali his dream of a new life in Europe became the nightmare that will haunt him till his own dying day.

Long before that moment on the cold winter waves of the Aegean he had watched his wife die and feared for his children as the barbaric fighters of the Islamic State (IS) group drew ever closer to the district in which they lived.

It was then that he decided, as any decent father would, that the time had come to spirit his loved ones to safety and make the journey to Europe where he would join his mother and sister already settled in Switzerland.

But for two of his four children that odyssey came to an end one night in the Aegean as the raft in which they were sailing foundered and sank spilling all on board into the waves.

For the next two hours Ali trod water, his three youngsters clinging to him for dear life. A fourth and eldest child still only 10-years-old had struck out for shore on his father’s orders, a swim that would save his own life.

During that interminable time in the water Ali watched helplessly as his youngest boy Hussein only six-years-old drifted off in the night sea.

As if this was not horror enough to contend with, later after struggling onto the beach frozen and exhausted with his two daughters, nine-year old Hawra and youngest child four-year-old Zainab, he would have to confront the fact that the ordeal had proved too much for Zainab who died shortly afterwards.

“My baby, I must go,” was all Ali said in broken English by way of unnecessary explanation as we stepped on board a motor launch in Kos harbour a few days after his son Hussein went missing at sea on what was to be a fruitless quest to find any clue as to the fate of his son.

“It’s not that he expects to find the boy, just that he feels a sense of guilt that he couldn’t save him and cannot leave without at least looking for Hussein’s body before he can continue on his journey to Switzerland,” said Yussef Walid, who accompanied us aboard the boat as a translator.

That afternoon as we scoured the isolated beaches around Kos I watched Ali Chadan’s hopes rise and fall with every sighting of what might have been the body of Hussein. To this very moment as I write there is still no trace of the boy.

Ali Chadan’s children were victims of a war, whose scale of its violence, and destructive power is something scarcely seen in decades.

In its course the war in Syria and Iraq has thrown up the worst refugee crisis in a quarter of a century, one eerily reminiscent of the dark days of the Second World War.

Statistics rarely convey the real measure of what war and its fallout means in human terms. The vile facts that Syria’s carnage has spewed out would however shock even the most cynically dismissive.

Over half of the country’s entire population has now been uprooted since the war took grip in 2011.

Inside Syria’s smouldering ruin of a nation some seven million people have been hounded from their homes by the dogs of war be they regime soldiers, opposition militias, jihadists of the Islamic State (IS) or airstrikes by warplanes of multiple air forces.

More than four million more ordinary Syrians have had enough of this rapacious onslaught and fled the country altogether.

As much of Europe’s position begins to harden toward those refugees seeking sanctuary, it is often forgotten just how many fleeing Syria have in fact chosen to stay in Turkey and other neighbouring countries rather than venture on to Europe.

For these people this has meant putting down temporary roots in places that though devoid of the barrel bombs and bullets, present living conditions scarcely better than those they experienced in Syria under conflict.

In reality of course this crisis doesn’t only stem from Syria. Likewise it is not acutely European, but rather a global crisis. According to the International Organisation for Migration (IOM) more than one million migrants and refugees have travelled to Europe in 2015, four times the total from last year.

By far conflicts in the Middle East and Afghanistan have been the driving force behind their flight.

Half of the total are thought to have come from Syria, 20 percent from Afghanistan, and 7 percent from Iraq.

European countries have struggled to handle the influx. Greece, Bulgaria, Italy, Spain, Malta, and Cyprus are all points of entry, but the vast majority, some 800,000, entered Europe through Greece, and almost all of them over the sea. The IOM also says 3,695 died trying to make these crossings in 2015.

"We must act. Migration must be legal, safe and secure for all, both for the migrants themselves and the countries that will become their new home," said William Lacy Swing, IOM's director general recently.

Faced with this the European Union (EU) has been confronted with an enormous challenge, with refugees testing the infrastructural capacities of many of Europe’s states, but also the idea of the EU and some of its core policies, including open internal borders.

Macedonia has tightened its border with Greece, and restricts passage to people from war zones. Germany alone has received one million migrants and refugees, many were already in Europe. Only last week the EU agreed to send more border agency staff to Greece. So this then is a story too about logistical and political struggles, revealing rifts within Europe and between communities.

Above all though it is a story full of human tragedy. Those refugees that I met who had embarked on their perilous journeys all had stories of great personal sacrifice, variations on the common themes of displacement, flight, exodus, exile and the loss of loved ones.

It is the constant uncertainty as well as the practical struggle to survive that haunts refugee lives.

“We lost everything, and almost lost our minds in Syria, we are in shock about what is happening,” Bassem a Syrian grandfather who fled his village home northwest of Hama with eight of his family told me when we talked in Kos.

The family had just made the sea crossing to the island from the same Turkish port of Bodrum near which the body of Alan Kurdi was found just a few months earlier

Over the course of the last few years Bassem’s family like so many Syrian refugees have known fear in all its forms.

Not that long ago one of his sons lost an eye from his injuries after missiles hit a field hospital near their village in Syria where he was helping move patients.

Another of his sons, Mohammed, who is 17-years-old still has a piece of shrapnel in his chest that needs removed. That day as I talked with the family Mohammed stood nearby listening before yanking up his shirt to show the scar tissue and lump where the metal is lodged.

“The most difficult thing is to put your feet inside the boat knowing the danger,” Bassem told me echoing the fears of the many families who had made the sea crossing before them.

As I said at the beginning of this piece I will never forget those people that I encountered while covering the story of Syria’s refugees this year.

Sadly I have little doubt that that I will be meeting many more in the year ahead, all of them blown by the winds of war to alien places and uncertain futures.