Editing Bohdan Khmelnytsky (section)

==Initial successes==
At the end of 1647 Khmelnytsky reached the [[estuary]] of the [[Dnieper]] river. On 7 December, his small detachment (300–500 men), with the help of registered Cossacks who went over to his side, disarmed the small Polish detachment guarding the area and took over the Zaporozhian Sich.{{citation needed|date=August 2015}} The Poles attempted to retake the Sich but were decisively defeated as more registered Cossacks joined the forces. At the end of January 1648, a [[Cossack Rada]] was called and Khmelnytsky was unanimously elected a [[hetman]]. A period of feverish activity followed. Cossacks were sent with hetman's letters to many regions of Ukraine calling on Cossacks and Orthodox peasants to join the rebellion, [[Khortytsia]] was fortified, efforts were made to acquire and make weapons and ammunition, and emissaries were sent to the [[Khan of Crimea]], [[İslâm III Giray]].
[[File:Envoy Jakub Śmiarowski to Bohdan Khmelnytsky, 1648 (unknown author, 17th century)-alternative version.jpg|thumb|Meeting of Khmelnytsky with the Polish envoy, 1648 (unknown author, 17th century)]]
Initially, Polish authorities took the news of Khmelnytsky's arrival at the Sich and reports about the rebellion lightly. The two sides exchanged lists of demands: the Poles asked the Cossacks to surrender the mutinous leader and disband, while Khmelnytsky and the Rada demanded that the Commonwealth restore the Cossacks' ancient rights, stop the advance of the [[Ukrainian Greek Catholic Church]], yield the right to appoint Orthodox leaders of the Sich and of the Registered Cossack regiments, and to remove Commonwealth troops from Ukraine.<ref>V. A. Smoliy, V. S. Stepankov. Bohdan Khmelnytsky. ''Sotsialno-politychnyi portret''. page 91, Lebid, Kyiv. 1995</ref> The Polish magnates considered the demands an affront, and an army headed by Stefan Potocki moved in the direction of the Sich.

Had the Cossacks stayed at Khortytsia, they might have been defeated, as in many other rebellions. However, Khmelnytsky marched against the Poles. The two armies met on 16 May 1648 at [[Battle of Zhovti Vody|Zhovti Vody]], where, aided by the Tatars of [[Tugay Bey]], the Cossacks inflicted their first crushing defeat on the Commonwealth. It was repeated soon afterwards, with the same success, at the [[Battle of Korsuń]] on 26 May 1648. Khmelnytsky used his diplomatic and military skills: under his leadership, the Cossack army moved to battle positions following his plans, Cossacks were proactive and decisive in their manoeuvrers and attacks, and most importantly, he gained the support of both large contingents of registered Cossacks and the [[Giray dynasty|Crimean Khan]], his crucial ally for the many battles to come.

===Establishment of Cossack Hetmanate===
[[File:Herb Viyska Zaporozkogo (Alex K).svg|thumb|upright|Coat of arms of the [[Cossack Hetmanate]]]]
The [[Greek Orthodox Patriarch of Jerusalem|Patriarch of Jerusalem]] Paiseus, who was visiting Kiev at this time, referred to Khmelnytsky as the Prince of Rus. In February 1649, during negotiations in [[Pereiaslav]] with a Polish delegation headed by Senator [[Adam Kysil]], Khmelnytsky declared that he was "the sole autocrat of Rus" and that he had "enough power in Ukraine, [[Podilia]], and [[Volhynia]]... in his land and principality stretching as far as Lviv, Kholm (modern [[Chełm]]), and [[Halych]]."<ref>V. A. Smoliy, V. S. Stepankov. Bohdan Khmelnytsky. Sotsialno-politychnyi portret, p. 203, Lebid, Kyiv. 1995</ref>

{{blockquote|I already did more than was thinking before, now I will obtain what I revised recently. I will liberate out of the Polish woe all of the Ruthenian people! Before I was fighting for the insults and injustice caused to me, now I will fight for our Orthodox faith. And all people will help me in that all the way to Lublin and Krakow, and I won't back off from the people as they are our right hand. And for the purpose lest you won't attack cossacks by conquering peasants, I will have two, three hundred thousands of them.|''(Bohdan Khmelnytsky, the Prince of Ruthenia)''<ref name="Hrushevsky,M 2003">[[Mykhailo Hrushevsky|Hrushevsky,M.]] ''History of Ukraine-Rus''. New ed. Bao. Donetsk, 2003.</ref>}}

After the period of initial military successes, the [[state-building]] process began. His leadership was demonstrated in all areas of state-building: military, administration, finance, economics and culture. Khmelnytsky made the [[Zaporozhian Host]] the supreme power in the new Ukrainian state and unified all the spheres of Ukrainian society under his authority. Khmelnytsky built a new government system and developed military and civilian administration.

A new generation of statesmen and military leaders came to the forefront: [[Ivan Vyhovsky]], [[Pavlo Teteria]], [[Danylo Nechai]] and [[Ivan Nechai]], [[Ivan Bohun]], [[Hryhoriy Hulyanytsky]]. From Cossack polkovnyks, officers, and military commanders, a new elite within the Cossack Hetman state was born. Throughout the years, the elite preserved and maintained the autonomy of the [[Cossack Hetmanate]] in the face of Russia's attempt to curb it. It was also instrumental in the onset of the period of [[Ruin (period of history)|Ruin]] that followed, eventually destroying most of the achievements of the Khmelnytsky era.

===Complications===
[[File:Bohdan-banner.jpg|thumb|Bohdan Khmelnytsky's banner that was taken at the [[battle of Berestechko]]. It was later taken by the Swedes in Warsaw 1655 and is now to be seen at Armémuseum, [[Stockholm|Stockholm, Sweden]].]]
Khmelnytsky's initial successes were followed by a series of setbacks as neither Khmelnytsky nor the Commonwealth had enough strength to stabilise the situation or to inflict a defeat on the enemy. What followed was a period of intermittent warfare and several peace treaties, which were seldom upheld. From spring 1649 onward, the situation turned for the worse for the Cossacks; as Polish attacks increased in frequency, they became more successful. The resulting [[Treaty of Zboriv]] on 18 August 1649 was unfavourable for the Cossacks. It was followed by another defeat at the [[battle of Berestechko]] on 18 June 1651 in which the Tatars betrayed Khmelnytsky and held the hetman captive. The Cossacks suffered a crushing defeat, with an estimated 30,000 casualties. They were forced to sign the [[Treaty of Bila Tserkva]], which favoured the Polish-Lithuanian Commonwealth. Warfare broke open again and, in the years that followed, the two sides were almost perpetually at war. Now, the [[Crimean Tatars]] played a decisive role and did not allow either side to prevail. It was in their interests to keep both Ukraine and the Polish–Lithuanian Commonwealth from getting too strong and becoming an effective power in the region.<ref name = "Subtelny">[[Orest Subtelny]]. ''Ukraine. A history.'' University of Toronto Press, p. 133. 1994. {{ISBN|0-8020-0591-8}}.</ref>

Khmelnytsky started looking for another foreign ally. Although the Cossacks had established their ''[[de facto]]'' independence from Poland, the new state needed legitimacy, which could be provided by a foreign monarch. In search of a protectorate, Khmelnytsky approached the [[Ottoman sultan]] in 1651, and formal embassies were exchanged. The Turks offered vassalship, like their other arrangements with contemporary [[Khanate of Crimea|Crimea]], [[Moldavia]] and [[Wallachia]]. However, the idea of a union with the Muslim monarch was not acceptable to the general populace and most Cossacks.

The other possible ally was the [[Tsardom of Russia]]. However, despite appeals for help from Khmelnytsky in the name of the shared Orthodox faith, the tsar preferred to wait, until the threat of a Cossack-Ottoman union in 1653 finally forced him to action.<ref name = "Subtelny" /> The idea that the tsar might be favourable to taking Ukraine under his hand was communicated to the hetman and so diplomatic activity intensified.