Boate (De Boote, Boet, Bootius, Botius), Arnold (1606–53) and , Gerard (1604–50), physicians and authors, were brothers, born in Gorinchem in the Netherlands, the sons of Godefroy de Boot and his wife Christina van Loon. Medical graduates of the University of Leiden, they settled in London in the 1630s as physicians, but clashed with the conservative College of Physicians. Arnold Boate published his first work on the Hebrew text of the Old Testament in 1636. His correspondence with Archbishop James Ussher (qv) may have prompted him to settle in Dublin (1636–44); his patients included Ussher and the lord deputy, Thomas Wentworth (qv). The brothers jointly published Philosopia naturalis reformata . . . (Dublin, 1641), a philosophical work critical of Aristotelianism. After the insurrection of 1641 Arnold acted as physician general for the government forces, one of his letters to his brother on Irish events being published as A remonstrance of divers remarkable passages (1642). On 25 December 1642 he married Margaret, daughter of Thomas Dungan (qv), justice of the common pleas; they would have three children.
Gerard subscribed to the adventure for Irish lands from 1642. By 1645 he had begun work on Irelands naturall history, at least in part to provide support for the possibilities of adventure-based plantation. Though he had not visited Ireland, he drew upon the observations of his brother, resident in London from May to October 1645, when he moved to Paris, and other prominent protestant figures from Ireland such as Sir William Parsons (qv). Gerard appears to have moved in scientific circles associated with Benjamin Worsley (qv) and the young Robert Boyle (qv). He was appointed physician general for the army in Ireland 17 July 1647, though he did not take up the post until 1649; by then he was also doctor to the military hospital in Dublin. He died in January 1650 and his papers passed to Samuel Hartlib, who published Irelands naturall history in 1652, with a letter from Arnold Boate prefixed.
Though only the first of Gerard's four projected books on the subject had been completed (the others were to cover the plant and animal life and the native customs of Ireland), his description of the natural, and aspects of the human, landscape has been regarded as setting new standards of precision in geographical writing. The utilitarian bias associated with Boate's intellectual circles is apparent in the work, as is a propagandist emphasis on the past, and potentially future, impact of English settlement, with much time taken up in consideration of ventures such as the ironworks sponsored by Sir Charles Coote (qv). Hartlib made unsuccessful efforts to have Boate's work completed, Arnold Boate being one of those involved. He had published further works on medicine and, more especially, on Hebrew textual studies, retaining Ussher's support in his controversies with European scholars. On his wife's death (April 1651) Arnold published a memoir, The character of a truelie vertuous and pious woman . . . He appears to have acted as a spy on English royalists in Paris for the commonwealth regime until 1653, the year of his death. Gerard's wife Katherine (née Menning, whom he had married in 1631) and his eldest son and heir (also Gerard) inherited 1,129 acres in Co. Tipperary in virtue of his investments under the adventure scheme.