Armenians refer to this chapter in their history as genocide -- a term the Turks firmly reject.
It's an issue that continues to blight relations between Armenia and Turkey. The two countries do not have diplomatic relations and the 268-kilometer border between the two countries has been closed since 1993.
Armenians say that Turks killed up to 1.5 millions Armenians in 1915-18 as the Ottoman Empire was beginning to crumble. Turks say the killings were part of the wider conflict of World War I, and that only 300,000 Armenians died.
Today, the controversy has gone global, with a number of countries debating whether the killings can be called genocide -- the deliberate and systematic destruction of a racial, political, or cultural group.
Many countries, including Russia, and Canada, have passed legislation recognizing the killings as genocide.
'I think we should live in the present, since there are more important issues, real issues, today.'
In the United States, many members of Congress -- dominated by the opposition Democrats -- have voiced support for a bill to officially recognize the Armenian killings as genocide. The bill has met with stiff opposition from supporters of the presidential administration, which is eager to maintain smooth ties with its NATO ally Turkey.
But even as the genocide debate has occupied international politics, some Armenians believe it's time for their country to move on.
Davit Gevorgyan, a 21-year-old computer programmer from Yerevan, says he thinks that pushing the issue of genocide is no longer appropriate.
"We should remember everything that's happened, but we don't need to use that to create a certain political course. I think we should live in the present time, since there are more important issues, real issues, today," Gevorgyan says.
"It would be better to solve these than to devote all our energy and efforts to those old issues. Many politicians are using the Armenian genocide to create their political platform in Armenia and it serves as a trump card, a way to manipulate people. They simply abuse it."
But politicians in both countries aren't likely to shift toward a more moderate stance on the genocide issue in the months ahead. Armenia holds parliamentary elections in May; Turkey will have presidential and general elections this year.
A dramatic policy switch on such an emotional issue could prove a massive political liability in a season when officials will be fighting to hold onto votes.
Soner Cagaptay, who heads the Turkish research program of the Washington Institute for Near East Policy in Washington, D.C., says that "the public is as staunch, in some ways, on this issue and in their entrenched commitments, as the politicians are."
An Armenian woman mourns the death of a boy during the deportation (epa)
Officially, Turkey has said that to establish diplomatic relations it would require Armenia to drop its policy on seeking recognition of the genocide internationally.
However, some Turkish politicians have said that Turkey should not attach such preconditions to the opening of the border.
That is mirrored by recent Armenian comments. Speaking at the OSCE in Vienna recently, Armenian Foreign Minister Vartan Oskanian said that in order to normalize relations with Turkey, the Armenian side has no preconditions and expects that Turkey should not have any either.
What complicates the issue is the powerful and wealthy Armenian diaspora. The diaspora has huge lobbying power in the West, particularly in the United States.
Cagaptay says that Armenia and the Armenian diaspora do not always have the same position.
"Armenia seems to be more pro-dialogue with Turkey -- unconditional dialogue, that is. Whereas the Armenian diaspora will not start a dialogue or a normalization of the relations unless Turkey unconditionally recognizes there is something called the Armenian genocide," Cagaptay says.
Another complication in relations between the two countries is Nagorno-Karabakh, the ethnic Armenian enclave that Azerbaijan, Turkey's traditional ally, and Armenia fought over in the beginning of the 1990s.
Despite the impasse, however, there are significant business links between the two countries.
The border, while officially closed, is quite porous in places. Traders also travel from Armenia via Georgia to sell their goods in Turkey. Some Armenians labor as guest workers in eastern Turkey and there are regular flights between Yerevan and Istanbul.
Many in the business community in Armenia and Turkey have lobbied for the border to be opened. They say it would have a huge effect in revitalizing poor regions on both sides of the border.
Noyan Soyak from the Turkish-Armenian Business Development Council says trade has grown significantly, from $35 million in 1997 to well above $150 million now.
"The free flow of people, the free flow of commodities, would definitely have a great impact on the development of the region, of the economical development of the region," Soyak says.
In the troubled relationships between Armenia and Turkey, there have occasionally been brief periods of hope for reconciliation.
Turkey's earthquake in 1999 was one of them, when Armenians sent truckloads of aid. The murder of Armenian-Turkish journalist Hrant Dink in January 2007, when tens of thousands of Turks turned out for his funeral, was another.
Turkey also recently completed a $1.5 million restoration of an ancient Armenian church located on an island on historic Lake Van in Turkey's eastern Anatolia region.
Turkey's prime minister, Recep Tayyip Erdogan, called the reconstruction a "positive" message. But a better one, suggested Armenian Foreign Minister Oskanian, would be to open the border.
(RFE/RL's Armenian and Azerbaijani services contributed to this report.)
'Every Armenian Knows What Happened To Their Ancestors'
By Harry Tamrazian, director, RFE/RL's Armenian Service
"To be Armenian and not know what happened in 1915 is unimaginable. Every Armenian, wherever they are in the world, knows what happened to their ancestors at the beginning of the 20th century. And every Armenian knows that almost the entire Armenian population in Turkey was lost because of an extremist, ethnocentric policy carried out by the government of the Ottoman Empire in 1915.
The issue will not go away. Armenians will not give up or compromise on their tragedy, which they firmly believe was a genocide." more
Do The Killings Constitute Genocide?
By Abbas Djavadi, director, RFE/RL's Azerbaijani Service
"Few in Turkey would deny that Armenians were killed in 1915 during the course of World War I. Opinions vary, however, on how the deportations and killings of Armenians came about; and whether the killings can be labeled a 'genocide' in a similar vein to the Holocaust.
While only a few extreme nationalists dispute the mass killings of Armenians, some liberals have recognized it as a 'genocide.' Most Turkish intellectuals, political analysts, and historians believe that local Armenians, with the help of Russia, were trying to create an independent Armenian state in eastern Anatolia. " more