This surname is derived from the name of an ancestor. 'the son of Isaac' A well-known personal name in the surname period, but no more confined to the Jews than Adam or Abel. Hundreds of English people bear one or other of these surnames in whose veins there flows not a single drop of Jewish blood.

Walter Isak, Somerset, 1 Edward III: Kirby's Quest.

Johannes Isakson, 1379: Poll Tax of Yorkshire.

Robert fil. Isaac, Lincolnshire, 1273. Hundred Rolls.

Isaac Judxus (the Jew), Yorkshire, ibid.

Johannes Isaak, Norfolk, ibid.

John Ysac, Oxfordshire, ibid.

William Isaak, Close Rolls 23 Henry VI.

1618. John Isick and Ursula Lawes, or Lawson: Marriage Lic. (London).

There is nothing Jewish in the following entry:

1745. Baptised — Thomas, son of Thomas and Barbara Isaac: St. James, Clerkenwell.

1790. Married — Richard Isaacs and Mary Peters: St. George, Hanover Square.

1808. — John Foster and Caroline Isaacson: ibid.

From the Hebrew yishaq, "he laugheth,' the name given to the son of Abraham and Sarah from the circumstances of his birth "A well-known personal name in the surname period, but no more confined to the Jews than Adam or Abel. Hundreds of English people bear one or other of these surnames in whose veins there flows not a single drop of Jewish blood" (Bardsley). The name was not uncommon among ecclesiastics in the twelfth and thirteenth centuries. Isaac was prior of Scone from 1154 till 1162 (Annals, p. 68), and Magister Isaac was a cleric of St. Andrews, 1201 (ibid., p. 334). Ysaac of Brechin was a charter witness there c. 1178—98 (REB., II, 257), and Ysaac de Banevin (Benvie) was one of a jury regarding the Kirketun of Aberbuthenoth, 1205 (SCM., V, p. 210). Isaac, son of Samuel, was one of the witnesses to the gift by Walter, son of Alan, to the monks of Scon, c. 1214 (Scon, p. 91), and Isaac, burgess of Aberbrothoc, witnessed a charter by Matilda, countess of Anegus c. 1242—43 (RAA I, p. 82). Isaac of Scone witnessed a quit-claim of the land of Drumkarauch in 1260 (RPSA., p. 346), and Gillandes Macysac witnessed a charter in favor of the priory of Beauly in 1231 (Beauly, p. 33). 'Sir Thomas Isaac was a witness in Edinburgh in 1358 (Bain, IV, 17), Andrew Isak of Scotland had a safe conduct into England in 1405, John Ysaac had a safe conduct to pass to France in 1447 (ibid., 687, 1203), and Thomas Esok was canon of a church of Argyll in 1448 (HP., II, p. 182). Thomas Esak was messenger-at-arms for Dunbartane in 1569 (RPC., I, p. 659), Jonet Isack was a witch in Kilwinning, 1662 (HP., III, p. 25), and in 1671 a charge of usury was brought against Robert Isack in Kirkcaldy (Just. Rec., II, p. 55). "A certain squire named Thomas Isaac" married Matilda, daughter of King Robert Bruce (Fordun. Annals, clxix). Concerning this singular mesalliance the late eminent genealogist, Mr. Alexander Sinclair, writes:"The name was not so low as it seemed. It was disguised into Ysac, Ysaac, and de Ysaac to make it appear noble This individual not long after had his name borne by gentry bearing the same name with coat armour, in the south of England. In Devonshire there were Isaacs of Buriat, temp. Henry III, who bore Sable, a bend or, on a canton argent a leopard's face gules. In 1460 there was also John Isaac of Bekesbourne, sheriff of Kent, who had the same arms, but the leopard's face or. Probably Thomas, the lucky adventurer was connected with one of these old families" (Herald and genealogist, VI p. 594). Isaac, clericus, was bailie and burgess of Aberdeen in 1332 (ER., I, p. 427). Eizack 1694.

'son of Isaac,' which see. Henry Isakisone in Huie in Unst, 1648 (Shetland).

Isaac’s (Son), Isaac’s Son v. Isaac.

(English) The son of Isaac (he who laughs).

This, as a baptismal name, was introduced about the time of the Conquest. One Isac appears as a chief tenant in Domesd. A few centuries later it was commonly 'nicked' to Hyke, Hicque, &c. Ultimately it gave rise to the various surnames of Isaacs, Isacke, Isaacson, Hike, Hick, Hicks, Hickes, Higgs, Higgins, Higginson, Hickson, Higson, Hixon, Hiscock, Hiscocks, Hiclcox, Hickie, and Hickey.

(Hebrew.) Laughter.

Contracted from MacIsaac, 'Isaac's Son' is rarely found except in the Isle of Man. Gilbert McIssak was one of the twenty-four 'Keys of Mann' in 1418, and in 1422 Hawley M’Issacke ' was arraigned for that he felloniously rose upon John Walton, Lieutenant of Mann, sitting in the Court of Kirk Michaell'.

Isaac is also an old Exeter name still represented in that city. Isacke or Isack was the name of the mayor of Exeter in 1665, and of two chamberlains of the city in 1653 and 1693 (I.) In the reign of Edward I. John Isaak lived in Wiltshire and Walter Isaac in Oxfordshire (H. R.), and the name occurs in Domesday. Devonshire is now the great home of the name, Isaacs being a rare form found in this county, but the name is also represented in Gloucestershire.