Thousands gathered Friday evening in Istanbul to mark the centennial of the mass killings of Armenians in Ottoman Turkey.

Armenians from around the world assembled in the evening sunshine at the entrance of central Taksim Square to remember the hundreds of thousands of their countrymen and women who died 100 years earlier in massacres and death marches as Turkish authorities forcibly deported them.

The event began with a smaller group hanging strips of cloth on a wooden "wishing tree," each representing a victim or survivor of the killings. A large crowd of chanting demonstrators arrived shortly afterward demanding that the events of 1915 be recognized as genocide. Turkish authorities are fiercely opposed to doing so, however, claiming instead that the deaths were the result of civil war that led to suffering on both sides.

A man ties a piece of cloth to the "prayer tree". (Photo by John Beck)

Many attendees were members of the Armenian diaspora and had travelled to Turkey especially for the ceremony as well as a preceding program of concerts lectures and memorial services. Some clutched photographs of their ancestors — both survivors and victims — and told the stories behind the sepia-toned faces.

Roxeanna Makasdjian, a red-haired 54-year-old from San Francisco who runs a nonprofit focused on human rights and genocide, held a picture of her great grandmother and two others aloft. They lived through the killings, she told VICE News, but others in her family did not.

Makasdjian described her attendance at the ceremony as being partly in a spirit of defiance. "This is where it all started and happened… We're here to show that the Turkish government at the time did not succeed in exterminating the Armenian people." She added, however, that she hoped increased recognition of the killings would help lead to reconciliation between Armenians and Turks.

Commemoration events were held around the world. In the Armenian capital of Yerevan, a ceremony was held at the Tsitsernakaberd Memorial Complex attended by local officials and foreign leaders, including France's Francois Hollande and Vladimir Putin of Russia. Armenian President Serzh Sargsyan said the Armenian people had been "displaced and annihilated under a state-devised plan."

Turkey, meanwhile, seemingly attempted to distract international attention away from centennial events in Armenia by staging its annual Battle of Gallipoli anniversary ceremonies a day earlier than usual.

Suzy Abajian holds pictures of her great grandmother and other relatives. (Photo by John Beck)

Armenia has been joined by a growing number of world leaders and international groups that define the killings as genocide. Turkish authorities insist that further research is required.

Historians generally agree about the facts of what took place, which are reflected in newspaper reports from the time.

Nevertheless, Turkey, a NATO ally, has reacted furiously when world leaders have dared to use the G-word. It withdrew its ambassador to Austria on Wednesday after Vienna did so, saying that relations between the two countries had suffered "permanent damage".

When Pope Francis described the deaths as the 20th century's first genocide at a mass earlier this month, Turkish President Recep Tayyip Erdogan warned him not to "repeat this mistake" and recalled its envoy to the Vatican.

Some world leaders have pointedly not used the term so as not to jeopardize relations with a valued ally. US President Barack Obama carefully avoided describing the killings as genocide in the lead up to the centennial events, despite pledging to do so when running for presidency in 2008.

Attendees at the Istanbul ceremony. (Photo by John Beck)

Erdogan himself expressed condolences to the victims last year, an unprecedented move that some hoped might lead to toward reconciliation. With a general election approaching in June, however, the president is now attempting to appeal to nationalist support, and only 9.1 percent of Turks wish to admit the killings were genocide, according to a January opinion poll by theIstanbul-based Center for Economics and Foreign Policy Studies (EDAM)

Both countries arguably still suffer from the lack of reconciliation and failure to move on from century-old politics. For Armenians, the sense of unresolved trauma is still keen. Suzy Abajian, a 39-year-old Syrian-born professor at LA's Occidental College who attended the Istanbul event, told VICE News that her great-grandmother was shot by Ottoman troops while carrying her baby on a forced march. The child died instantly and she only survived by remaining silent even when the soldiers tore her earrings out to check if she was feigning death.

Abajian said that she now feels forever homeless, haunted by her people's history and undermined by Turkey's refusal to take responsibility. "If you look at the US, nobody challenges the Holocaust and says 'well there are two sides to it,'" she said with visible emotion. "You couldn't imagine that kind of discourse, but we've had to engage in that forever and still to this day. When something like this has gone unrecognized and unacknowledged, it continues to define the whole community."