In 1069 he succeeded in placing Izaslaus on the throne of Kiev, thereby confirming Poland's overlordship over Russia and enabling Boleslaus to chastise his other enemies, Bohemia among them, with the co-operation of his Russian auxiliaries.
With the Teutonic knights, still Poland's most dangerous foe, Casimir preserved peaceful relations throughout his reign.
Czarniecki is rightly regarded as one of the most famous of heroic Poland's great captains, and to him belongs the chief merit of extricating her from the difficulties which threatened to overwhelm her during the disastrous reign of John Casimir.
In less than twenty years after the death of its founder, it collapsed before a combined attack of all Poland's enemies, and simultaneously a terrible pagan reaction swept away the poor remnants of Christianity and civilization.
The Great (1333-1370), Poland's first great statesman in the modern sense of the word, who, by a most skilful system of matrimonial alliances, reintroduced isolated Poland Casimir III.
A second Tatar raid in 1259, less dangerous, perhaps, but certainly more ruinous, than the first invasion - for the principalities of Little Poland and Sandomir were systematically ravaged for three months - still further but Poland formed but a small portion of his vast domains, and Poland's interests were subordinated to the larger demands of an imperial policy which embraced half Europe within its orbit On the death of Louis there ensued an interregnum of two years marked by fierce civil wars, instigated by duke Ziemovit of Masovia, the northernmost province of Poland, the daughter of Louis the Great and the granddaughter of Wladislaus Lokietek, had an equal right, by inheritance, to the thrones of Hungary and Poland.
Had that dynasty been prolonged for another century, there is every reason to suppose that it would also have dealt satisfactorily with Poland's still more dangerous internal difficulties, and arrested the development of that anarchical constitution which was the ruling factor in the ruin of the Republic. Simultaneously with the transformation into a great power of the petty principalities which composed ancient Poland, another and equally momentous political transformation was proceeding within the country itself.
A strongly centralized government had ever been Poland's greatest need, and Casimir the Great had striven successfully against all centrifugal tendencies.
He was full of the idea of a league of republics against the league of sovereigns; but he was unaware that the Jacobins themselves were already considering the best mode of detaching Prussia, Poland's worst enemy, from the anti-French coalition.
No remnant of Poland's separate political existence Poland a remained save the minute republic of Cracow.
Wladislaus's first official act was to march against the Muscovites, who had declared war against Poland immediately after the death of Sigismund, and were besieging Smolensk, the key of Poland's eastern frontier.