The history of Khmelnytskyi starts with the human settlement of the city, which has been attested to since the Bronze Age. The area was then successively inhabited by various cultures, but it would not be until 1431 that the city was first mentioned by Władysław II Jagiełło in a grant as Płoskirów. Płoskirów, during early Polish rule, would remain a small village, with a 1493 register of the Podolian Voivodeship mentioning just over a hundred people. In 1547, Płoskirów was granted to Maciej Włodek of Hermanów, who then developed the village and helped it achieve Magdeburg rights in 1566. A castle was then built in the city in the 1590s, known as the Płoskirów Castle. During the Khmelnytsky Uprising, Płoskirów variously changed hands between the Cossacks and Poles, resulting in the destruction of the city, which was further compounded by raids on it as part of the Polish–Cossack–Tatar War (1666–1671). In 1672, following the Siege of Kamenets, Płoskirów became part of the Ottoman Empire within the Podolia Eyalet. Ottoman rule would not last long, and it was returned to Polish rule by 1699 with the Treaty of Karlowitz. After this, the starostwo of the Zamoyskis resettled Płoskirów with ethnic Poles known as the Mazurs. In 1793, as part of the Second Partition of Poland, the city was then annexed into the Russian Empire as part of the Podolia Governorate and renamed to Proskuriv or also Proskurov.
Like during Polish times, Proskuriv remained a relatively minor city in comparison to the much larger city of Kamianets-Podilskyi. This began to shift in 1870 with the opening of railway lines in the city, which led to Proskuriv rapidly industrialising and also becoming militarily important again, thanks to the stationing of units. By the early 1900s, Proskuriv had become the largest trading centre in the Podolia Governorate. However, during the subsequent Ukrainian War of Independence, which was part of the Russian Civil War, the city constantly saw action, changing hands between the Ukrainian People's Republic, Bolsheviks, Imperial Germans, White movement, and Poles. Notably, the city was the site of the Proskurov pogrom during the war, in which forces under the UPR killed around 1,000 to 1,600 Jews. It was also a temporary capital of the UPR for a time in March 1919, when the Sich Riflemen were also stationed in the city, until the UPR decided to retreat to Rivne. Bolshevik control was consolidated in late 1920, and the city was annexed into the Soviet Union in 1922. During the interwar period, the city was industrialised again, but it was also the site of repressions by the NKVD, which shot 2,060 people during the Great Terror. Proskuriv was made the administrative centre of Khmelnytskyi Oblast shortly before the war in March 1941.
During World War II, after the start of Operation Barbarossa, Proskuriv was occupied by Nazi Germany as part of Reichskommissariat Ukraine from 8 July 1941 to 25 March 1944. During this time, the city was the site of a prisoner of war camp known as Stalag 355, where over 60,000 Soviets were killed. Also, as part of the Holocaust, 9,500 Jews were massacred by the Germans. Proskuriv was liberated in March 1944 as part of the Kamenets–Podolsky pocket. After the war, the city was renamed from Proskuriv to Khmelnytskyi in 1954 in honour of Bohdan Khmelnytskyi. Khmelnytskyi was then made a military city again, hosting the 19th Zaporizhzhian Missile Division of the 43rd Rocket Army, with Khmelnytskyi itself being host to 10 intercontinental ballistic missiles, specifically UR-100s. After the collapse of the Soviet Union, the city became part of an independent Ukraine. During Euromaidan protests in 2013-14, the city was the site of massive protests, with over 7,000 people rallying at Independence Square in January 2014. The Khmelnytskyi Oblast Council building was occupied by protesters in February, during which two protesters were shot, including Liudmyla Sheremet. Despite these events, Khmelnytskyi continued to grow. After the Russian invasion of Ukraine, the city became a major hub for internally displaced people from the frontlines, but has also been the site of multiple Russian attacks, which have killed at least three.
Antiquity Settlements in the area of modern-day Khmelnytskyi have been extensively attested to in multiple districts of the city. In the eastern part of the city, in the Lezneve microdistrict, materials dating to the Bronze Age and Scythian eras have been found, and in the northern part of the city, in Ozerna, a multi-era settlement has been found starting in the early Iron Age. Other examples include, in the centre at Dubove, Scythian material; from the western part of the city in Hrechany, materials from the Chernyakhov culture, and numerous kurgans from the Scythians that survive in multiple microdistricts, such as Zarichchia and Rakove. One of the more recent artifacts to be found in 2020 near the Nativity of the Theotokos Cathedral was a fragment of a ceramic vessel that dates back to around the 6th-8th centuries AD. The fragment found was 3.6 metres and was suggested to be evidence that the area was visited periodically, and not permanently, during this time.
Founding of Płoskirów
The first written mention of the city when it was known as Płoskirów dates back to 10 February 1431, when King Władysław II Jagiełło issued in the town of Sopot a royal grant that gave the nobleman Jan Chanstulowski a few villages for the sum of 100 hryvnias. The villages mentioned in this grant are Holysyn (now Oleshyn) and Płoskirowce, which were near the Boh river in the district of Letychiv within Podolia. This is recorded in the Lithuanian Metrica, which states in the original text in Latin, "super villis Holissini et Ploskirowcze super fluvio Boh iacentu in terra Podoliensi et districtu Laticzowiensi sitas." Although Mykhailovsky notes that a separate village also known as Płoskirowce (now Proskurivka) also existed, which could be mistaken for the settlement described as Płoskirowce, the folios consistently record Holysyn as being on the opposite bank of the Boh from Płoskirów, making it impossible for it to be Proskurivka, since that settlement was farther south. Płoskirów/Płoskirowce would again be mentioned four more times prior to 1493 in the Lithuanian Metrica as a royal estate granted out to nobles under tenure. The first time was during the subsequent reign of Władysław III of Poland from 1434 to 1444, when the possession of the settlement is mentioned; the shortened name of "Płoskirów" rather than "Płoskirowce" was first used, which marks the point Płoskirowce began to fall out of use. Płoskirów was again then mentioned in a 16 December 1461 grant by Casimir IV Jagiellon to his servant Mikołaj Śwircz of Bedrychowiec, a Stolnik of Kamieniec Podolski, granting "Płoskirów..in the district of Międzybóż" for 50 hryvnias. The last two times Płoskirów was mentioned pre-1493 was in 1464 and 1470. In the latter, the estate of Śwircz, which was given to his heirs Ivan and Mikołaj de Czessilow, was granted to the castellan of Kamieniec Podolski, Mikołaj z Nowego Dworu of Horodok.
In the 1493 Register of Hearts of the Podolian Voivodeship, which was a tax document, Płoskirów is recorded as having seven households with just over a hundred people and was a wooden-fortified point. This was, until Mykhailovsky's research in 2004, widely considered the founding date of the city, and was the date that the city's 500th anniversary in 1993 was celebrated with badges. Nevertheless, the town would remain relatively insignificant in comparison to the nearby historical capital of Podilia, Kamieniec Podolski, until 26 March 1547 when Sigismund II August, as coregent, granted a lifetime grant of "Płoskirów, Leśniów, and Holyszyn with their environs, lying on the Boh in the Kamieniec district" to Maciej Włodek of Hermanów and the starosta of Kamieniec Podolski as a reward for his military service. In 1550, this was converted into a hereditary grant.
Early Polish rule and Płoskirów Castle
After Włodek became the city's ruler, the population grew threefold, from 100 in 1541 to nearly 300 in 1569, according to estimates based on the voivodeship's tax register. By this point, there is already some evidence of a castle in the city, at least according to a royal property survey of starostwo of the Kaminiec notes that the residents of the small village of Trykhivtsi, as part of labour duties, were required to serve a castle in Płoskirów, among others. In 1566, thanks to the efforts of Włodek, Płoskirów was also granted Magdeburg rights, although this was only partially complete, as the city still remained under the authority of the starosta despite having its own town-hall administration. Włodek eventually died in 1570, and the estate was left to his son, Stanisław, who continued his father's efforts to improve the new city, with King Stefan Batory in 1578 granting Płoskirów a new privilege of hosting annual fairs in addition to its weekly Tuesday markets.
The founding of the Płoskirów Castle is, according to Yesyunin, dated to when Bernardo Morando, during his time as the engineer of Lwów in 1589, traveled to Płoskirów with Stanisław Szembek. Yesyunin claims that upon Morando visting, Włodek requested of his relative Jan Zamoyski (Włodek was married to Zamoyski's sister, Elżbieta Zamoyska), the then Hetman of the Polish-Lithuanian Commonwealth, that Morando help fortify Płoskirów also. This was apparently granted, and according to Yesyunin, Morando helped rebuild the old castle into the modern Płoskirów Castle, which was said to be designed in a grand stone bastion style that Morando had used at Zamość. However, this is contested, as Zakhar'yev argues that the castle was only ever described as small, and not a grand project. If anything, Zakhar'yev argues it was Stanisław himself who worked on rebuilding the castle by damming the Buh to turn the town into an island, and that Morando had minimal contributions to the actual project and instead just raised the earthen ramparts and erected a wooden palisade with towers. Either way, the oldest surviving subsequent eyewitness account of the town is dated to 1594 by Erich Lassota von Steblau, who was an envoy of Maximilian III of Austria. He described Płoskirów in this account as being situated on a lake that lay on the Boh that naturally divided the town in half.
Khmelnytsky Uprising and destruction In the early 1600s, the settlement came into dispute when Stanisław, with consent, transferred Płoskirów to Jan Potocki of Bracław, and after Potocki's soon death, his widow ceded it to Stanisław Lanckoroński of Podolia. Jakub Potocki, the brother of Jan, together with his cousins Mikołaj and Jan, formally protested this transfer, although Lanckoroński eventually just gave a large sum to the Potockis. Upon Lanckoroński's death, it was passed on to, rather notably, Stanisław Koniecpolski, who possessed the estate until 1646. Under his tenure, Płoskirów had its first Jews come to the city in 1627, and two years later the city was recorded as having 1,300 people (although this does not include the garrison stationed at Płoskirów Castle). In 1646, the estate was inherited by Aleksander-Michał Lubomirski, who ceded it to Koniecpolski's son, Aleksander Koniecpolski, who held the estate at the start of the Khmelnytsky Uprising. At the start of the uprising, in September 1648, the insurgent Cossack leader Maksym Kryvonis marched towards Pyliavtsi, and on the way stormed through the Płoskirów Castle and destroyed its garrison. A year later, another Cossack regiment under Danylo Nechai defeated the forces of Stanisław Lanckoroński (he is not the same estate holder mentioned earlier) outside Płoskirów. During this time, generally, the city changed hands multiple times between the Cossacks and Poles, and was completely devastated as a result of the fighting.