The locative surname “de Ergham” appears to stem from the parish of Argam or Ergam, near Bridlington in East Yorkshire.  The first reference to Erghams in relation to Preston comes in 1373 when Ralph de Erghum was listed as warden of St Mary Magdalen’s Hospital in the town. In 1374 he was appointed Vicar of Preston; according to one source, he appears to have delegated the responsibility as shortly afterwards he was appointed Bishop of Salisbury. Another possibility, suggested by Abram, is a Lancashire origin. He notes that in the time of Edward I, towards the end of the 12th century, Arkholme in Melling Parish was spelled Erghum. 
A John de Ergham was listed as an in burgess on the 1397 guild roll, along with his son, Adam. This strongly suggests that John was established in the town at the time of the previous guild (date unknown but given the custom of the guild possibly in the late 1370s). The 1397 guild roll also includes William de Ergham as mayor and fined burgess, as well as his sons Robert, Geoffrey and William. The fact that he is described as a fined burgess, that is, he was sponsored for burgess status by two other burgesses and paid an entry fine, means that he was not a burgess at the time of the previous guild and neither was his father and suggests that he became established in the town after that guild. Fishwick includes him in his list of the town’s mayors in 1388, 1396-97, 1402, 1408, 1413, 1416-19 and 1425; Fishwick adds that Patten House in Church Street was built on the site of “Ergham’s Manor House”, but gives no source.
An indication of William de Ergham’s prominence in the town is given by the fact that he was guild mayor at the 1397 guild. Regulations applying to the guild at this time would seem to preclude burgesses who were not in the previous guild roll from holding office; this should have debarred William and other fined burgesses from office but clearly did not, indicating that the guild regulations were either not routinely enforced or that William and the other fined burgesses gaining office had sufficient authority to negate this particular regulation. William is listed as the proposer of new burgesses to the guild rolls 19 times. In 17 of these entries he is the first proposer, more than any other burgess; a fact that might be a status indicator. The rapid rise to prominence of William de Ergham in his adopted town would appear to parallel that of John Horrocks, 400 years later.
The Ergham family could have continued living in Preston until well into the 16th century. According to Fishwick, citing Kuerden, a W. Ergham was a steward at the 1500 guild. In 1540 Isabella Ergham married Henry Preston and a William Erram gent appears on the 1582 guild roll; Henry Preston’s son Henry is recorded in his post mortem inquisition of 1601 as having bought Aram House from William Aram, gent, who Fishwick identifies as William Argham, son of Richard Argham, who both appear on the 1562 guild roll. The progression from de Erghum in 1373 to Aram in 1601 by way of Argham and Erram seems quite likely. This would make Aram House a more probable site of “Ergham’s Manor House” than Fishwick’s suggestion of Patten House.
Aram House would presumably have abutted the Aram’s Backside that was later renamed Molyneux Square. A deed of 1439 refers to “the Hopgreave towards Erghum sike”.Another deed of 1522 refers to “a close called … Erghom Hey’ (de Hoghton deeds: 327 and 339)