This surname is derived from the name of an ancestor. or nick. 'Michaelmas'; compare Candlemas, Pentecost, Whitsunday, Christmas, Nowell, Saturday, &c, from the day or season whereon or wherein the child was born. The evidence in favour of this origin is sufficiently strong, although I suggest another interpretation infra. For one thing we find one undoubted instance:

1547. Shorman Myglemas: Churchwarden's Accounts, Ludlow (Camd. Sot, v. Index).

Michaelmas was commonly so pronounced. In the Treatise of Fishing with an Angle, in the St. Alban's Book, the following are given as baits for roach in July, 'the not worme, and mathewes, and maggotes tyll Myghelmas': Sign. i. ii (v. Promptorium Parvulorum). For further proof v. Mighill. From Migglemas to Middlemas would be an easy transition. The final 't' in Middlemast and Middlemost would thus be excrescent.

(a) Nick, or local, 'the middlemost,' i.e. the middle one in the family, or the middle house in a row of cottages, 'at the middlemost' We find this somewhat uncouth superlative in Ezek. xlii. 5, 'the middlemost of the building.' Still earlier, c. 1450, we find it in some curious nursery lines upon the fingers (v. fingers, Halliwell), wherein the little finger is styled 'litylman,' and the longest' longman.' 'Longman hat the mydilmast, for longest fynger hit is.'Stolen from Fore bears

1694. Married — Moses Pearrpoint and Mary Midlemass: St. James, Clerkenwell.

1700. — Searles Middlemas and Elizabeth Court: Canterbury Cathedral.

The Middlemasses were vassals and tenants of the district around Kelso, and derived their surname from "lie Middlemestlands in villa et territorio de Calco," mentioned in 1029 (Retours, Roxburgh, 137). William de Meldiemast who petitioned for a benefice in the gift of the abbot of Kelso, 1406 (Pap. Pet., I, p. 624) was probably Schir Wilyeam Myddilmast, the "lwvit chapellain" of Archibald de Douglas, earl of Wigtoun, vicar of Selkirk in the first quarter of the fifteenth century (PMS., II, 59). King James II confirmed a charter by William Myddilmast, vicar of Lynton, of certain tenements in the town of Peblis 1439 (Peebles, p. 207-208). Thomas Myddilmast is recorded in Ploro, 1495 (Trials, I, p. 20), and John Myddilmest witnessed a charter by Robert, abbot of Kelso, 1497 (Kelso, p. 429). Thomas Myddilmaist of Grestoune, a Peeblesshire laird, 1530 (Trials, I, p. 147). Thomas Middlemast was retoured heir in 1566 in the lands of Middilmast as "Middlemast of Middlemast," and Mege and Malie Middilmest were tenants under the Abbey of Kelso in 1567 (Kelso, p. 520,525). David Midlmest is in record in Mairbotle (Morebattle) in 1652 (Inquis., 3701), and Luckie Middlemist kept a famous oyster-cellar in Edinbergh in latter half of eighteenth century. This surname has been recently absurdly explained as from "middlemast," obsolete English for "mainmast," and so a nickname for a very tall man. Medillmest 1537, Medilmaste and Middilmaste 1425, Middelmest 1611, Middlemist 1742. Midelmest 1610, Midilmest 1611, Midlemes 1612, Midlemiss 1665, Midlemist 1670, Midlmess 1674, Mydilmest 1513.

MIDDLEMAS, Middlemass, Middlemiss: The Middlemasses were vassals and tenants of the district around Kelso, and derived their surname from "lie Middlemestlands in villa et territorio de Calco," mentioned in 1029 (Retours, Roxburgh, 137). William de Meldiemast who petitioned for a benefice in the gift of the abbot of Kelso, 1406 (Pap. Pet., I, p. 624) was probably Schir Wilyeam Myddilmast, the "lwvit chapellain" of Archibald de Douglas, earl of Wigtoun, vicar of Selkirk in the first quarter of the fifteenth century (PMS., II, 59). King James II confirmed a charter by William Myddilmast, vicar of Lynton, of certain tenements in the town of Peblis 1439 (Peebles, p. 207-208). Thomas Myddilmast is recorded in Ploro, 1495 (Trials, I, p. 20), and John Myddilmest witnessed a charter by Robert, abbot of Kelso, 1497 (Kelso, p. 429). Thomas Myddilmaist of Grestoune, a Peeblesshire laird, 1530 (Trials, I, p. 147). Thomas Middlemast was retoured heir in 1566 in the lands of Middilmast as "Middlemast of Middlemast," and Mege and Malie Middilmest were tenants under the Abbey of Kelso in 1567 (Kelso, p. 520,525). David Midlmest is in record in Mairbotle (Morebattle) in 1652 (Inquis., 3701), and Luckie Middlemist kept a famous oyster-cellar in Edinbergh in latter half of eighteenth century. This surname has been recently absurdly explained as from "middlemast," obsolete English for "mainmast," and so a nickname for a very tall man. Medillmest 1537, Medilmaste and Middilmaste 1425, Middelmest 1611, Middlemist 1742. Midelmest 1610, Midilmest 1611, Midlemes 1612, Midlemiss 1665, Midlemist 1670, Midlmess 1674, Mydilmest 1513.

For Michaelmas (English) One born on 29TH September [Middle English michelmesse, mighelmesse, &c.: v. Michael and + Old English mæsse]

A corruption of Michaelmas, which is so pronounced in some dialects. Other corrupted forms of the word, employed as surnames, are Middlemist and Middlemast. Probably from the person having been born at that festival. So Christmas, Easter, Pentecost, &c.

From Middlemarsh; a location name in Lincolnshire.