In 1800, the region of present-day Syria had a population of approximately 1.25 million people. Growth was relatively slow during the 19th century, and the population reached just over two million by the time of the First World War in 1914. However, population would begin to grow more rapidly following the beginning of French occupation in 1920, and by the time Syria achieved independence from France in 1946, the population would be just over 3.2 million. Following the country’s independence, Syria would begin experiencing exponential growth, the result of significant economic growth from the country’s growing petroleum exports.

However, the 21st century would see a sharp reversal of Syria’s exponential population growth, with the beginning of the Syrian Civil War after widespread anti-government protests in 2011. After peaking at 21.4 million people in 2010, Syria’s population would see a rapid decline during the civil war, as widespread conflict, massacres, and destruction would lead to significant fatalities and a mass exodus of refugees from the country, with several million migrating to neighboring Turkey, Lebanon, and Jordan, and another several hundred thousand ultimately migrating to the European Union. As a result, the population of the country has declined greatly, falling from over 21 million in 2010 to just under 17 million by 2018. However, as the fighting has gradually decreased in intensity and refugee rates have levelled off, the population of Syria has slowly began to grow again. In 2020, Syria is estimated to have a population of 17.5 million people.

In 1800, the region of present-day Turkey had a population of approximately 9.8 million. Turkey’s population would grow steadily throughout the 1800s, growing to 14 million by the turn of the century. During this time, Turkey was the center of the Ottoman Empire, which also covered much of the Balkans, Arabia, and the African coast from Libya to Somalia. In the early 20th century, the Ottoman Empire's dissolution period began, characterized by political instability and a series of military defeats and coups. The empire was one of the defeated Central Powers of the First World War, in which it suffered approximately three million total fatalities. It is estimated that the majority of these deaths did not come directly from the war, but as a result of the government-orchestrated mass expulsion and genocide of non-Turks from within the Turkish borders, specifically Armenians, Assyrians, Greeks and Kurds; many ethnic Turks were simultaneously expelled from neighboring countries, namely Greece, which makes these events less-visible when examining annual data, although Turkey's total population did drop by one million between 1914 and 1924.

The Republic of Turkey Following the end of the Turkish War of Independence in 1923, and the establishment of the republic of Turkey, the population would begin to recover, tripling from just around 21 million in 1950 to over 63 million by the turn of the century. The new republic, led by Mustafa Kemal Atatürk, introduced sweeping, progressive reforms that modernized the country, particularly its healthcare and education systems. Turkey remained neutral throughout the Second World War, and became a member of NATO during the Cold War. The second half of the 1900s was marked with intermittent periods of political instability, and a number of military conflicts (namely, in Cyprus and Kurdistan). In spite of this, Turkey has generally been considered a developed country for most of this time, although its life expectancy and infant mortality rates have often been more in line with developing nations.

Modern Turkey In the past decade, Turkey's population growth has continued its rapid growth; while birth rates have declined, the mass migration of refugees to the country fleeing the Syrian Civil War has seen the population growth ramain high. This influx of refugees was seen as a stepping stone in Turkey's accession to the European Union, with whom it has been negotiating a potential membership since 2005. Accession to the EU would provide huge economic benefits to Turkey, however, political developments in recent years (particularly the 2016 coup) have seen these negotiations stall, as the EU has accused the Turkish government of committing widespread human rights violations, such as torture, political imprisonment and censorship of free speech. In 2020, Turkey's population is estimated to be over 84 million people, and is expected to exceed 100 million in the next two decades.