(Cambridge Concise Histories) Jerzy Lukowski, Hubert Zawadzki - A Concise History of Poland-Cambridge University Press (2006)

It was on Lithuania’s northern and eastern borders that the most ambitious and most fateful of Jagiellonian foreign policy initiatives was to unfold. The enfeoffment of Ducal Prussia in 1525 had settled, at least for the time being, the Crown’s most vexatious problem. To the north of Lithuania lay the Livonian lands controlled by the Teutonic Order’s sister organization, the Knights of the Sword. By the 1550s, these territories were largely Lutheran and the Knights virtually a secular institution, acknowledging a vestigial allegiance to the Holy Roman Emperors. Though Livonia grew rich on trade and tolls from Lithuania and Muscovy, the Knights’ endless quarrels with the archbishop of Riga made for political weakness. It was all very tempting for Ivan IV, who regarded Livonia as part of his Rurikid inheritance. Should it fall into his grasp, he would have a boulevard to the Baltic and be placed to threaten Lithuania from the north as well as the east. Sigismund Augustus showed great interest in Livonia, not just for its strategic importance, but because its wealthy cities might provide new resources for his chronically hard-up monarchy.

Sigismund initially hoped to impose some form of vassal relationship, which would secure him what he called ‘dominium maris Baltici’ - ‘mastery of the Baltic Sea’. Yet his Polish and Lithuanian lands were ill prepared for the sustained, large-scale warfare that conflict in the region was to demand. For a start, Polish military and fiscal support was very fitful: the Poles were only interested in providing continuous support at the price of the full incorporation into Poland of Livonia. That, of course, remained anathema to most of the Grand Duchy’s elite, who saw in Livonia a purely Lithuanian prize, compensation for the loss of Smolensk. Sigismund would have liked to have got his way by a combination of military bluff and diplomatic wheeling and dealing, but real warfare was impossible to avoid. By massive alienations of royal domain, loans, by occasional, inadequate tax grants from the Polish and Lithuanian parliaments, by calling on the retinues of individual magnates or even the pospolite rnszenie, he was able to put together an impressive artillery park and to mass substantial numbers of troops for individual campaigns, but never to keep them on the constant war-footing required (though his enemies had the same problems). A series of understandings between the Livonian Masters, the archbishop of Riga and Sigismund between September 1557 and November 1561 progressed from an agreement on mutual assistance to the outright incorporation of Livonia into the Polish Crown. The Order was secularized. Its last Grand Master, Gotthard Kettler, received the territory of Courland, running along the southern bank of the Dvina river, as a hereditary duchy and fief of Poland.

Sigismund was powerless to deflect the ferocious invasions which were Ivan IV’s response. In 1558, the Russians captured Narva and Dorpat, and in 1560 the centrally located town of Fehlin, although they failed to take the strategically crucial port of Riga. Distractions against the Crimean Tatars and Ivan’s decision in 1563 to switch his main war effort directly against Lithuania helped stave off outright conquest. Ivan was also wary of the involvement of other parties. Denmark showed a close interest in the area. In 1561, the port of Reval, mistrusting the shortcomings of Sigismund’s military efforts, submitted to the ambitious Erik XIV of Sweden, whose forces began to extend Swedish rule throughout Estonia.

Ivan's diversion against Lithuania eased the pressure on the luckless Livonian lands, but it cost the Grand Duchy the fortress of Polotsk, which fell in February 1563. It was not, however, the Lithuanian victory over the Russians on the river Ula in 1565 which led to a prolonged lull in the fighting. Rather it was renewed Tatar onslaughts (which, in 1570, saw much of Moscow destroyed by fire), and Ivan’s disastrous inauguration of the Oprichnina, the reign of terror against his domestic enemies, real and imagined, in January 1563. From July 1566, a kind of truce prevailed between Moscow and its Polish-Lithuanian protagonists. Sigismund Augustus’ forward policy had foundered: more Lithuanian terri-tory than ever was under Russian occupation; Livonia was torn between chaos with Swedish occupation in the north, Polish and Lithuanian garrisons in the south and west and Russian forces in the centre. The repercussions went further; fishing for support in the Empire, Sigismund had, in March 156}, agreed that, should Albrecht of Prussia’s line fail, Ducal Prussia could revert to the electoral, Brandenburg branch of the Hohenzollerns. Thus did the 1525 treaty of Krakow begin to be jeopardized by the Jagiello-nians’ own brand of imperial overstretch.