George Buchanan (Scottish Gaelic: Seòras Bochanan; (born: February 1506) was a Scottish historian and humanist scholar. According to historian Keith Brown, Buchanan was "the most profound intellectual sixteenth century Scotland produced." Buchanan was a Catholic who committed himself to the Reformation. He was tutor to the great French essayist Michel de Montaigne, to Mary Queen of Scots, and, later, to her son, the boy who was to become King James VI of Scotland and I of the United Kingdom. For mastery of the Latin language, Buchanan has seldom been surpassed by any modern writer. His style is not rigidly modelled on that of any classical author, but has a freshness and elasticity of its own. His translations of the Psalms and of the Greek plays are more than mere versions; his two tragedies, Baptistes and Jephthes, enjoyed a European reputation for academic excellence. His Pompae verses were written for performance at the court entertainments of Mary, including the Offering of the Rustic Gods sung during a masque devised by Bastian Pagez for the baptism of King James. In addition to these works, Buchanan wrote in prose Chamaeleon, a satire in Scots against Maitland of Lethington, first printed in 1711; a Latin translation of Linacre's Grammar (Paris, 1533); Libellus de Prosodia (Edinburgh, 1640); and Vita ab ipso scripta biennio ante mortem (1608), edited by R. Sibbald (1702). His other poems are Fratres Fraterrimi, Elegiae, Silvae, two sets of verses entitled Hendecasyllabon Liber and Iambon Liber; three books of Epigrammata; a book of miscellaneous verse; De Sphaera (in five books), suggested by the poem De sphaera mundi of Joannes de Sacrobosco, and intended as a defence of the Ptolemaic theory against the new Copernican view. The first of his most important late works was the treatise De Jure Regni apud Scotos, published in 1579. In this famous work, composed in the form of a dialogue, and evidently intended to instil sound political principles into the mind of his pupil, Buchanan lays down the doctrine that the source of all political power is the people, that the king is bound by those conditions under which the supreme power was first committed to his hands, and that it is lawful to resist, even to punish, tyrants. The second of his larger works is the History of Scotland, Rerum Scoticarum Historia, completed shortly before his death, and published in 1582. It is remarkable for the power and richness of its style, and of great value for the period personally known to the author, which occupies the greater portion of the book Less