King Jan III Sobieski was well-known beyond the frontiers of the Commonwealth mainly as an outstanding commander in chief. It is therefore not at all surprising that in his book, an Irish physician to the king, Bernard O’Connor dedicated a lot of his attention to the Polish army. O’Connor had no military education, nevertheless his account remains highly precise and detailed as the author based his work on earlier publications of inter alia Szymon Starowolski. O’Connor tackles separately the levy in mass with its structure, ways of summoning and categories of people precluded from the compulsory service. He then moves on to describe the regular troops divided into the cavalry, the infantry, and finally their weaponry. In his account O’Connor also discusses the question of fortresses [forts], by noticing that they are too scarce and in a poor condition. He dedicates most of his attention to the combat value of the Polish army. By referring to some victories, among them the 1588 Battle of Byczyna fought against the troops of Archduke Maximilian III Habsburg and the 1605 Battle of Kircholm fought against the Swedish troops, O’Connor makes a high evaluation of the Polish armed forces, especially the cavalry. Despite the quoted victories and his recognition of Sobieski’s military genius, O’Connor also enumerates weak points, which do not result so much from insufficient valour or military skills as rather from poor organisation. In his opinion, the chief drawback is lacking discipline, stemming from irregular pay, appointment of unskilled and inexperienced hetmans and a total incapability to keep secrets, even by the highest ranking commanders. Nevertheless, O’Connor observes that these issues can easily be solved and that the Commonwealth is not at all doomed to military defeat. Of all units, he is most impresses by the winged cavalry of Hussars. He notes that, ‘Both the Hussartz and Tovarzysz, with their Horses, look frightfully, being stuck all over with Wings of Storks, Cranes, Turky-Cocks, etc. and Cloath’d over their Armour with skins of Leopards, Tygres, Bears, Lyons, etc. all which they do to make themselves the more terrible to their Enemy.’ O’Connor was not the only foreigner to admire the winged cavalry. Some fifty years earlier, a French diplomat Charles Ogier remarked that, ‘All the Polish nobles, seated on beautiful steeds, wearing fine and shiny armour covered with panther, lion or tiger skins, hold long lances fastened with leather straps that hang from the saddles; at the end of the lances near the head, there are silk sashes or pennants which flutter in the wind and confuse the enemy’s eyes.’ Other foreign travellers to the Commonwealth evaluated the condition of the local army in a similar manner to O’Connor’s. On the one hand, they emphasized huge capabilities, as exemplified by the account of the French historian Michel David de La Bizardière towards the end of the 17th century. Although very critical of Poles, he nevertheless observed that, ‘Whoever tries to arouse fear in Poles shall only harm themselves, as Poles are too valiant to fear any nation; in fact, no nation would dare to do what even Romans themselves never dared.’ On the other hand, foreigners stressed imperfect organisation, depreciating the value of the Polish army. The secretary of the French Embassy, M. de Mongrillon expressed a temporarily common opinion when he observed that, ‘Should soldiers be paid on regular basis, military service in Poland would be of prime value. [Poles] have a small infantry, very poor engineers and insufficient knowledge of sieges.’ Some of the charges were justifiable, as financial arrears to the army were often very large. In 1661 they amounted to 24 million zlotys of arrears to the army of the Crown alone. Other charges however, especially those concerning the lacking fortresses and insufficient infantry, stemmed from incorrect understanding of the Polish situation. Fortresses played a key role in defence systems in Western Europe. As exemplified by the conflict between France and the United Provinces, military action was mainly focused on besieging fortresses, with the key tasks performed by the infantry. Due to long distances and a far smaller density of population, in Central and Eastern Europe fortresses were not of such importance, with the army’s mobility being the victory-determining factor. Consequently, cavalry was developed at the expense of infantry. Political elites in the Commonwealth were well aware of the organization-related problems. The ill-fated Silent Sejm of 1717 introduced a system of regular investments in the army from fixed financial sources. Thus, it nullified the earlier practice of determining in successive sejm sittings the sum of taxes dedicated to military spending. Despite that move, the army of the 18th-century Commonwealth, comprising roughly 18 thousand soldiers, was clearly weaker from military forces of the neighbouring states. In case of war there were as many as 350 thousand soldiers ready for action in Russia, 200 thousand in Prussia and 280 thousand in Austria. The Polish weakness resulted from political reasons. The gentry did not opt for a more powerful army due to their pacifist attitude as well as their fear that the king could take advantage of a large army to strengthen his own position and eventually to create an absolute monarchy. In fact, this problem was known in other countries too. Driven by identical fears, in 1689 England passed an act prohibiting the state from keeping an army in the time of peace without the parliamentary consent. England also seriously considered a complete liquidation of its regular forces and their replacement with a militia, an equivalent of a levy in mass. However, England and later Great Britain had two chief assets, missing in the then Poland. When in need, England could buy entire troops in the continent. Admittedly, it was a costly solution as between 1739 and 1756 as much as 17.5 million pounds were spent on the purpose, equalling the unimaginable sum of 647.5 million zlotys. Besides, Great Britain was an island and not a state surrounded by three ‘cordial neighbours’. Consequently, the Commonwealth required its own large army, which the state could, but eventually never chose to, have.