When Jan Sobieski was elected King of Poland, France was probably the most satisfied of all states concerned. According to Queen Marie Casimire, the French ambassador and Bishop of Marseille, Forbin-Janson ignored instructions received from Paris and supported Sobieski, undoubtedly helped to the throne by his recent victory in the Battle of Chocim [Khotyn]. On receiving the news of Sobieski’s election, Louis XIV issued the following declaration: “One may say that no earlier election in Poland was shinier than this. It is a true miracle that heavens [...] wished to grant them [i.e. Louis XIV and France] their grace by supporting their longest-standing and best friend.” The joy displayed by the King of France was genuine, as he was in a bad need for an ally. On engaging in war against the Netherlands in 1672, Louis did not expect the Empire, Spain and Brandenburg to turn against him. Poland could cause trouble for the anti-French coalition if Sobieski was talked into opposing the emperor in his attempt to regain Silesia or to invade Ducal Prussia.
Sweden was equally satisfied with Sobieski’s election. Charles XI sent to Poland his envoy Andreas Liliehöök, equipped with an instruction containing among others the king’s promise of military support in case of war against Turkey. The envoy’s task was to strive for a defence alliance between Poland and Sweden. After Sweden backed France and Swedish troops marched into the Empire, the state was in danger of war waged by the Elector of Brandenburg. Another threat was created in the east by Moscow which constituted an equally dangerous of Poland’s neighbours. In this light, Sobieski’s decision to invade Ducal Prussia would be favourably received by France and consequently, French diplomacy tried to direct Poland’s military action in this direction. Nevertheless, the plan laid down by French ambassadors was “from another planet”, to say the least. It assumed Swedish troops occupying Ducal Prussia and Polish forces launching military action in Brandenburg Pomerania. After the war ends, the two states would share the spoils. Sobieski feared that after occupying Prussia, Sweden would refuse to leave it. Therefore, in February 1675 he submitted a letter to the Swedish court demanding that the territory to which Poland claimed its rights be left intact.
Top secret negotiations lasted one year. Although there is no factual evidence to prove it, it is fairly possible that the talks were held by Michał Hacki, officially employed as a tutor of pages at the royal court and unofficially as a secret secretary of Jan III Sobieski. There is no other way to explain the fact that the address delivered by the Swedish envoy at the occasion of Sobieski’s election in Warsaw was published by the Cistercian print shop in Oliwa, Father Hacki’s home monastery. Probably some of the negotiations were conducted in Gdańsk, or even in a secluded place inside the Oliwa abbey. As a matter of fact, Liliehöök stayed in Gdańsk in October 1674 , in February and March 1675, and then at the turn of December 1674 and January 1675 he visited Sopot owned by the Cistercian monks.
In compliance with the Treaty of Yavoriv signed on 11 June 1675, Jan III Sobieski pledged to declare war against the Elector of Brandenburg immediately after attaining peace with Turkey. Meanwhile, Sweden invaded Brandenburg and on 28 June 1675 its troops were defeated near Fehrbellin. The triumphant Elector of Brandenburg marched into Pomerania and effortlessly occupied successive Swedish dominions. The Swedes could only be saved by attacking Ducal Prussia which required an agreement with Poland and its allies. At that time, the Commonwealth was already in the state of war against Turkey and Sobieski was too responsible a politician to engage in two simultaneous wars. Besides, Poland was a parliamentary monarchy, leaving the king with no right to make decisions without the sejm’s consent.
King Sobieski strong wished for the Crown to regain Ducal Prussia. Meanwhile, during the coronation sejm session held in February 1676 some senators led by Andrzej Trzebicki, the Bishop of Cracow and Vice-Chancellor of the Crown, voted in favour of the pro-Austrian orientation, i.e. the ongoing war against Turkey, thus opposing King Sobieski’s plans. The sejm left the king to decide on agreements with the neighbour states. This translated into the monarch’s freedom in shaping mutual relations between the Crown and the Elector of Brandenburg. After the sejm session was adjourned, in March 1676 Sobieski sent to the elector his most astute secretary, Father Michał Hacki. Officially, the royal envoy was to present the elector with the notification of the royal coronation and a list of demands resulting in Brandenburg failing to redeem its obligations towards the Commonwealth. Unofficially however, Hacki was to obtain information on the elector’s forces in Pomerania and the progress of war activities.
Father Hacki was sent to the elector for the second time in August 1677 when he presented the demand for liberating Aegidius Strauch, a priest from Gdańsk. He went on the same mission again in October 1677. According to the elector, Hacki’s task was to figure out how long Szczecin would hold out the invading Brandenburg troops (besieged since October 1676, the city surrendered in December 1677). The event thwarted Sobieski’s Baltic plans. The ineptitude of Swedish commanders, total chaos within the troops and ill will did not bode well for future cooperation between the two states. This was coupled with Polish nobles displaying reluctance to the royal plans, additionally stirred by agents of Brandenburg circulating in the Commonwealth and last but not least, the emperor’s diplomacy.
The final victory was achieved near Vienna with the support of the Holy See. In 1679 Sobieski gave up his Baltic plans, focusing instead on (eventually unsuccessful) efforts to establish a Christian league against Turkey. Diplomatic missions sent by the 1679 sejm to France, England, Austria, Venice, Rome and Moscow failed. Instead, they increased vigilance of Louis XIV who opposed the idea. Austria treated Sobieski’s project with reserve, but changed its mind when Turkey won the war against Moscow and signed the Treaty of Bakhchisarai on 13 January 1681. Talks launched between Poland and Vienna alarmed France and its agents led by Jan Andrzej Morsztyn, Grand Treasurer of the Crown. The pro-French party cantered around Morsztyn was not only willing to scuttle efforts of the Austrian diplomacy, but eventually to dethrone the king.
Sobieski’s opponents and their activities were kept under control by Father Hacki. His vigilance was helped by an agreement stipulating that all post from Poland was sent via Gdańsk. The post office in Gdańsk was headed by Paweł Gratta, general postmaster of Royal Prussia, Courland and Livonia. He personally opened and copied encrypted letters of French ambassadors, which were later deciphered by Hacki. Thus, King Sobieski was well informed of all moves made by his opponents. In the spring of 1683, when the sejm was to ratify the alliance between Poland and Austria, the opposition tried to disrupt the session, but in the course of negotiations the French faction was exposed. Morsztyn was accused of high treason and misappropriation of funds. On 1 April 1683 the alliance was finally ratified. The emperor pledged to abandon his claims to the Polish throne and to pay 1 200 000 zlotys for military purposes. Poland in turn was to mobilize an army of 40 thousand soldiers and to embark on joint military action against Turkey. The alliance was made under the Pope’s patronage.
We do not know, and probably never will, the true role of Michał Hacki, the inconspicuous monk from Oliwa, in re-orienting King Sobieski’s politics. The question is all the more legitimate that Hacki was a clergyman and consequently subordinate to the Holy See, probably maintained personal contacts with the Pope (initiated when he was a chaplain and lived on the charity of Christina, Queen of Sweden). Above all, the question is legitimate because Hacki’s name appears on various “payrolls” of the Viennese court. Its first appearance on the list of extraordinary items of the emperor’s chancellery expenses takes place on 3 May 1683 when Hacki received the sum of a thousand Rhine florins. He was paid the same sum on 28 June 1683.