Their constant aim was to shake off Polish suzerainty, and in 1520-21 their menacing attitude compelled Sigismund to take up arms against them.
The rules, however, also provide that in case of invasion the inhabitants of a territory who on the approach of the invading enemy spontaneously take up arms to resist it, shall be regarded as belligerent troops if they carry arms openly and respect the laws and customs of war, although they may not have had time to become organized in accordance with the above provisions.
That the prince should have felt compelled in the last resort to take up arms for the Union against the attempt of the province of Holland to defy the authority of the Generality may be justified by the plea reipublicae salus suprema lex.
During this first period of their dealings with India the aims of the British were purely those of traders, without any aspirations to military power or territorial aggrandizement; but in the period that followed, the gradual decay of the Mogul empire from within, and the consequent anarchy, forced the English to take up arms in their own defence, and triumphing over one enemy after another they found themselves at last in the place of the Moguls.
Bethlen no sooner felt firmly seated on his throne than he seized the opportunity presented to him by the outbreak of the Thirty Years' War to take up arms in defence of the liberties and the constitution of the extra-Transylvanian Hungarian provinces, with the view of more effectually assuring his own position.
In revenge for his own imprisonment, and the death of his brother by order of Nero, he took advantage of the disorder in the empire not only to stir up his fellow-countrymen to take up arms for independence, but to persuade a large number of German and Belgic tribes to join forces with them.
The Holy See, jealous of the growing power of the house of Luxemburg, attempted to set aside the decrees of the congress of Visegred, by urging Casimir to take up arms against the knights once more; but Casimir prudently refrained from hostilities, and ultimately compensated himself in the southeast for his losses in the north.
In 1211 the boy was entrusted to Montfort's care to be educated, but the aggressions of the crusaders on the princes of the south forced Peter to take up arms against them, and he was slain at Muret on the 12th of September 1213.
He was finally compelled to take up arms against his Kumanian friends, whom he routed at Hodmezd (May 1282) with fearful loss; but, previously to this, he had arrested the legate, whom he subsequently attempted to starve into submission, and his conduct generally was regarded as so unsatisfactory that, after repeated warnings, the Holy See resolved to supersede him by his Angevin kinsfolk, whom he had also alienated, and on the 8th of August 1288 Pope Nicholas IV.
Arriving in Dublin at the end of October he received information to the effect that seventeen counties were ready to take up arms if a successful effort were made in Dublin.