Steward arms, detail from monument of Robert Steward (d.1570) in Ely Cathedral. 

Genealogy
The descent of Robert Steward (d.1570) is as follows, per Heraldic Visitation of Cambridge, 1575 (Clay, J. W., ed. (1897). The Visitation of Cambridge made in Anno 1575, continued and enlarged with the Visitation of the same county made by Henery St George, Richmond Herald, marshall and deputy to Willm. Camden, Clarenceulx, in Anno 1619, with many other descents added thereto. Harleian Society, 1st ser. 41. London, pp.7-11, pedigree of "Stuart" [1]):

John Steward, the first of the Scottish family to have settled in England (supposedly having been shipwrecked in East Anglia whilst sailing with a son of the King of Scotland, and then held hostage by the English), married Mary Talmache (Tollemache ?), an English virgin with whom he fell in love during his captivity;
Sir John Steward, son, who married a daughter of Sir Thomas Keyriell
Thomas Steward of Soham, son, who married a daughter of SirJohn Hamerton
Richard Steward, son, who married the daughter and heiress of John Boreley (who quartered Walkfare)
Nicholas Steward of Wells, Norfolk, son, who married Cicelia Baskerville, daughter and heiress (Steward quartered Baskerville) of ....... Baskerville of ......
Simeon Steward of Lakenheath in Suffolk, son, who married Joan Besteney, daughter and heiress of Edward Besteney of Soham in Cambridgeshire. His brothers included Robert Steward (d. 1557), Dean of Ely, and w:Edmund Steward (died 1559), Dean of Winchester.
Sir w:Mark Steward (1524-1604), 3rd son, of Heckfield in Hampshire and of Stuntney in Cambridgeshire. Brother of Robert Steward (1526/30-1570), both with monuments and effigies in Ely Cathedral.Heraldry
Arms quarterly of 9 (source: Clay, J. W., ed. (1897). The Visitation of Cambridge made in Anno 1575, continued and enlarged with the Visitation of the same county made by Henery St George, Richmond Herald, marshall and deputy to Willm. Camden, Clarenceulx, in Anno 1619, with many other descents added thereto. Harleian Society, 1st ser. 41. London, p.7 [2]) (NB curiously the many quarterings of Baskerville (which appear on the monument to his brother Sir w:Mark Steward (1524-1604) also in Ely Cathedral, are here omitted entirely):

1: Argent, a lion rampant gules debruised by a bend raguly or (Steward, augmentation of honour) w:Augmentation of honour to the arms of Steward given by the French King Charles VI (1368-1422) to Sir Alexander Steward "The Fierce" (a grandson of w:Alexander Stewart, 4th High Steward of Scotland (died 1283), from whose first son were descended all the Stuart kings of Scotland), for service done by his father Andrew Steward to that king and to the king of Scots, and also to John the French king, grand-father to Charles VI. Evidently alludes to the following event. An armed knight foughtwith a lion, and having broken his sword, which lay in fragments at his feet, snatched up a rude club with which he  combatted the beast. In allusion to this, in some books the following crest is given to the Steward family A sword broken in two, the pieces placed in saltire on a wreath, and surmounting a ragged staff erecly or. (Source: Archaeologia: Or Miscellaneous Tracts Relating to Antiquity, 1777, pp.183-5[3])
2: Vert, three boar's heads couped argent (Boreley) (Burke, Sir Bernard, The General Armory, London, 1884, p.101 "Boreley / Borseley of Wiltshire")
3: Argent, a lion rampant sable on the shoulder a mullet or (Walkfare) (Burke, Sir Bernard, The General Armory, London, 1884, p.1066 Or / argent, a lion rampant sable "Walkfare of Norfolk")
4: Per pale sable and gules, a lion rampant guardant argent crowned or (Bestney) (Burke, Sir Bernard, The General Armory, London, 1884, p.78  "Bestney of Hertfordshire") Visitations gives: Per pale gules and sable, a lion rampant argent crowned or on the shoulder a crescent of the second (Bestney); Pedigree of "Bestney of St. Albans, Hertfordshire" (probably today's "Beeson End, Redbourn", 4.7 km north of St Alban's Abbey, see Rev. C. More, 'Catalogue of field names occurring on the Hertfordshire estates of the Earl of Verulam', Transactions of the St. Albans and Hertfordshire Architectural and Archaeological Society, 1927, pp.19-20[4]) as reported to the 1634 Visitation of Hertfordshire, Appendix II, p.126[5]: Per pale sable and gules, a lion rampant guardant argent ducally crowned or. Descended from Edward Bestney "of West Bestney", Constable of Flint Castle in Wales.
5: Argent, a cross flory sable between four martlets of the second (Spenlow) (source: Clay, J. W., ed. (1897). The Visitation of Cambridge made in Anno 1575, continued and enlarged with the Visitation of the same county made by Henery St George, Richmond Herald, marshall and deputy to Willm. Camden, Clarenceulx, in Anno 1619, with many other descents added thereto. Harleian Society, 1st ser. 41. London, p.7 [6]) (Spenlow of St Albans, Hertfordshire (1634 Visitation of Hertfordshire, Appendix II, p.126[7])) (heiress of "Bestney of Hertfordshire") (here shown as Cornish choughs proper, which would be "Philips of Shropshire" (Burke, p.800)) (not listed in Burke). 
6: ? Argent, two pallets and three barrulets between nine fleurs-de-lis sable ?  (an heiress of Spenlow ?)
7: Vert, three lions passant or a mullet of the last (FitzGeffrey) (an heiress of Spenlow ?) (not listed in Burke)
8: Azure, a chevron ermine between three leopard's faces or (Blackney (per Visitation of Cambridge)) (Blackney of Cropley Hall, Hertfordshire, heiress of Spenlow (1634 Visitation of Hertfordshire, Appendix II, p.126[8]) (here with chevron or) (Burke, Sir Bernard, The General Armory, London, 1884, p.87 Sable, a chevron ermine between three leopard's heads or "Blackney of Norfolk")
9: Argent, a lion rampant guardant sable within a bordure (engrailed) of the second (Beruen) (heiress of "Bestney of Hertfordshire") (Burke, Sir Bernard, The General Armory, London, 1884, p.76 "Beruen/Berven/Berwen") (heiress of "Bestney of Hertfordshire")
Enhanced image from photo by Budby [9]
This enhanced image by Lobsterthermidor (talk) 22:47, 27 November 2021 (UTC)