The Mainwaring family held a prominent place among the Cheshire gentry for over five hundred years, although their influence rarely extended beyond the county. Through marriage alliances with other Cheshire families they developed their estates throughout the 15th and 16th centuries. In 1400 John Mainwaring had land or was drawing rents from land in Baddiley, Brindley, Burland, Chester, Eaton, Faddiley, Hulme Walfield, Lawton, Peover, Stoke, Upton and Poulton in Wirral. In 1405 the family acquired lands in Chelford and Dittington, and deeds from 1444 refer to Mainwaring interests in Aston, Baddiley, Chester, Fouleshurst, Nantwich, Newhall, Peover and Withington. The estates were centred on Peover, where the halmote court met.
Throughout the 15th century the family was active in local administration, serving as sheriffs of Cheshire, tax officials and commissioners. Sir John Mainwaring I (d. 1483) supported the Lancastrian cause, associating himself with two prominent Lancastrians, James Touchet, Lord Audley, and Humphrey Stafford, Duke of Buckingham. Mainwaring entered an agreement to serve the latter in peace and war. Sir John's great grandson, Sir John Mainwaring II (d. 1516), was one of the Cheshire gentry who granted a subsidy of one thousand marks towards the war with Scotland and was appointed sheriff of Flintshire in 1506. He was knighted for his service in the French campaign of 1513.
Sir Thomas Mainwaring (1623-1689), 1st baronet, antiquary and local politician, inherited the family estates in 1647. He was assiduous in local committee work, becoming a JP in 1649, sitting as a commissioner for assessment, the militia, and the regulation of ministers, and serving as sheriff in 1657-8. He sat for Cheshire in the Convention Parliament. After the Restoration he was reappointed to his local offices, nominated to the order of the Royal Oak, and created a baronet on 22 November 1660. Between 1675 and 1681 he served as a deputy lieutenant for Cheshire. Sir Thomas loved books and cultivated learning. Between 1673 and 1679 he and his kinsman Sir Peter Leycester exchanged insults and arguments in print over the illegitimacy of their remote common ancestress, Amicia, daughter of Hugh of Cyfeilog, earl of Chester, alleged in Leycester's Historical Antiquities (1673) and denied by Mainwaring. Eventually their arguments ranged over much of the social and political life of the twelfth century, and in so doing represented a milestone in historiography.
Sir John Mainwaring (1656-1702) was the fourth but oldest surviving son of Sir Thomas Mainwaring. He succeeded to the baronetcy and sat as a whig in six Parliaments between 1689 and 1701. He married Elizabeth (d. 1719), eldest daughter of Roger Whitley of Peel in Cheshire on 28 September 1676. They had five sons, four of whom died young or without issue, and two daughters. He died in debtors' prison on 4 November 1702.
Source: Hans Norton, 'Mainwaring, Sir Thomas, first baronet (1623-1689)', Oxford Dictionary of National Biography, Oxford University Press, 2004. By permission of Oxford University Press - http://dx.doi.org/10.1093/ref:odnb/17813.