This study is the result of a forty-five-year-old brick wall in my family history, culminating in an effort to find and record all references to the names Tilliduff (my great-grandmother was Eliza Tilliduff) and Tullideph and thirty (to date) other spellings of the name. The study is registered with The Guild of One-Name Studies, who are hosting this site. If you are connected to the 
Tilliduff or Tullideph families and would like to contact me please do so through my Guild profile page.
While trying to complete my own family tree I have also been attempting to answer the following questions: Where did the Tilliduff name come from? How many Tilliduffs are there now? How many were there? Where are, and were, they? How many different spellings of the name are there? And are they all related?
The name comes from the former barony of Tillydaff to the north-west of Aberdeen, Scotland, in Midmar (not to be confused with Tillyduff, mentioned in place-names around St. Combs and Crimond further to the north-east). The name is Celtic, meaning “hill of the oxen or deer”. (In 1760 Walter Tullideph, having purchased the estates of Balgay and Baldovan in Dundee, noted that “The Highland name of Tullideph signifies Hindhill, so I shall call Balgay that and the other Tullideph Hall.” He chose a stag’s head as his crest.) The old barony comprised the areas of Orchardtown, Rothmaise, Ranieston and Logierieve in addition to Tillydaff (marked on the map below, which will enlarge on clicking). The Tillydaffs “of that ilk” lived at Orchardtown, but any sign of a house had disappeared by the 19th century.
The direct line died out in 1628 with the death of the last of the Tillydaffs of that ilk, Marjory Tullydaff, who had married William Seton of Disblair, and the lands of Tillydaff were inherited by William Seton her son. However, by then there were members of the family in Fife who were the ones to carry on the name until it reached England in the mid-18th century with the arrival in London of my five-times great grandfather Robert Tullideph.
In all I have 206 names of people born with the name (and 30 different spellings, although only two which became the standard form – Tullideph and Tilliduff) dating from the earliest mention in 1317. In fifty per cent of the names I have proved relationship with the records available and formed a tree dating from 16th century, while in other cases, mainly in the 15th – 16th century records, I have linked parents to children but am unable to connect them further. However, in view of the restricted locations in which the family is to be found I believe them all to stem from the same family.
The name Tullideph as a surname was extinct early in the 19th century with the will of Jean Gall, widow of John, being the last entry in Scotland in 1823, and the son Robert of the above-mentioned Robert Tullideph having been recorded as Tillyduff in London on the births of his children, with subsequent generations bein
g Tilliduff. By the time of the 1881 census there were just 16 Tilliduffs recorded, all of them in Kent and London. (Two were spelled “Tiliduff” and one recorded as Henry T. Duff). South Africa is the only country where the name still exists, with just one family carrying the name. Tullideph is still being carried down some lines as a middle name, (and even as a first name in one case) one line of which is descended from David Tullideph’s daughter Ann, b. 1736, who married William Procter, two from Thomas’s daughter Mary, 1741 – 1785, who married Thomas Bisset, and another from Walter’s daughter Charlotte, 1736 – 1810, who married John Ogilvy, 5th Baronet of Inverquharity. 
This site operates confidentiality guarantee: we hide from public view anyone born within the last 100 years whom we do not know to have died