Turkmenistan

Merv — the Silk Road's greatest oasis city

Merv (c. 500 BCE – 1221 CE) — the ancient oasis city in the Murghab River delta, known to Greeks as Antiochia Margiana, to Arabs as Marw al-Shahijan ("Merv the Great"), and to medieval travellers as the world's largest city at its 12th-century peak with a population of perhaps 500,000 — was the crossroads of Central Asia, the meeting point of Persian, Hellenic, Buddhist, Christian, Zoroastrian, and Islamic civilisations before the Mongols annihilated it.

The Seljuk Empire — Merv as the world's capital

The Great Seljuk Empire (1037–1194 CE) — the Turkic dynasty that conquered Persia, Iraq, and Anatolia from Central Asia, established the sultanate as the dominant power over the Abbasid caliphate, defeated the Byzantine Empire at Manzikert (1071), and precipitated the Crusades — made Merv its imperial capital in the 12th century, when it may have been the world's most populous city.

The Mongol destruction of Merv — the greatest massacre in history

The Mongol sack of Merv (February 1221 CE) — in which Tolui Khan's forces spent several days methodically killing the population after the city surrendered — is described by contemporary sources as the largest single massacre in pre-modern history, with Persian chronicler Ibn al-Athir writing that "the world has not seen, and perhaps will not see, a greater catastrophe" and estimates of dead ranging from 700,000 to 1.3 million.

Russian conquest and Soviet Turkmenistan

The Russian conquest of Turkmenistan (1881–1924 CE) — completed with the Battle of Geok Tepe (1881), where Mikhail Skobelev's forces stormed the Tekke Turkmen fortress after tunnelling under its walls and detonating 4,000 kilograms of explosive — incorporated the last independent Turkmen territory into the Russian Empire and eventually into the Soviet Turkmen SSR, which collectivised the nomadic Tekke, Yomut, and Ersari tribes into collective cotton farms.

The Darvaza gas crater — burning for half a century

The Darvaza gas crater ("Door to Hell") in the Karakum Desert (1971–present) — a 70-metre-wide, 20-metre-deep hole that has burned continuously for over fifty years after Soviet geologists accidentally punctured a natural gas cavern, expecting it to burn out in weeks — has become Turkmenistan's most famous landmark and the world's most dramatic accidental industrial monument, drawing adventurous tourists to a country that otherwise minimises foreign visitors.

Turkmenbashi — the world's most bizarre personality cult

Saparmurat Niyazov's rule as "Turkmenbashi" ("Father of all Turkmens") (1991–2006 CE) — during which he renamed months after himself and his mother, banned beards and car radios, built a rotating golden statue of himself in Ashgabat that always faced the sun, prescribed his self-written spiritual text (the Ruhnama) for school curricula and driving tests, and created a totalitarian state of astonishing personal idiosyncrasy — was the post-Soviet era's most extreme personality cult.