Brithdir hamlet is in the north-east of the parish, and covers the area of the parish between Nant Bargod Rhymni and the Rhymney river. The main communities in this hamlet today are Pontlottyn, Tirphil and Brithdir plus that part of Deri east of Nant Bargod Rhymni. This was divided into 19 farms of between 36 and 293 acres, plus two plots of land of 833 acres and 253 acres which had previously been agricultural but which by 1841 was occupied by The Rhymney Iron Company. There was also much land that was common land.
The boundries of the Hamlet in 1750 were given as it begins where Bargod River goes to Rumney by Aberbargod bridge then along the River Bargod upwards till it comes very near the way upon the common that leadeth from Kevan y Brithdire to Twyn y wayn then directly westward to the three stones in the heath below Twyn y wayn between Merthyr and Gellygare then directly to the east side of Twyn y wayn then directly to Fynnon Gwelliw then to the old water pond in Pant y wayn coal pits then directly to the spring head of a brook called nant y Glaynon then to Pwll llwchmeare then to carn y clyndir or mark ycha then to carn helig then to Rhyd yr Milwr on the river Rymney then along the river Rymney to Aberbargod bridge aforesaid".
The industrial revolution arrived in Gelligaer in Pontlottyn and this is reflected in the population figures. The population in each sucessive census was 1801 - 278, 1811 - 257, 1821 - 391, 1831 - 792, 1841 - 1835, 1851 - 2362, 1861 - 3879, 1871 - 5636. By 1881 population was no longer recorded by hamlet as their function had all but disappeared.
The farms as recorded in the 1841 tithe schedule are shown below. Many of these names still appear on the modern OS map although now sometimes referring to a village rather than a farm. So we now have Pontlottyn (a village), Ty Newydd (disappeared), Dyffryn farm, Troedrhiwfuwch farm (a village of that name has now gone), Craig-Rhymney farm, Tirphil (a village), Tyla-ddu, Brithdir-uchaf and Brithdir-isaf are now forrested, Troed-y-rhiw Jestyn (a farm), Coed Deri-Newydd (forrested, some of the land is part of the village of Deri), Pen-y-fid Fedw (now forrested) ,Tyr-capel (a farm), Cefn Bach farm, Groes-faen farm (parts of both Cefn Bach and Groes-faen are forrested), Tir Evan Thomas now Plas Milfre, Cefn-y-brithdir (a farm), Brithdir which was also known as Brithdir-ganol has been absorbed into neighbouring farms and the village of Brithdir, Tir-y-ferch-gryno (a farm), Gwaelod-y-brithdir (a farm).
The tithe value has been converted to modern pounds/pence; it gives an indication of the relative values of the farms in 1841
|Farm name||Acreage||Tithe value||Owner||Tenant|
|Blaen Rhymney||833 acres||£38.15||Marquess of Bute||Rhymney Co.|
|Duffrin Rhymney||253 acres||£6.85||Capel Hanbury Leigh||Rhymney Co.|
|Pont Lottyn||132 acres||£2.30||Edmund Williams||various tenants|
|Ty Newydd||44 acres||£2.20||British Iron Co.||Abraham Morgan|
|Duffryn Rhymney||213 acres||£5.5||Edmund Williams||William Davis|
|Troedrhiw'r ferch||158 acres||£4.65||Elizabeth Williams||Rhymney Co.|
|Craig Rhymney||77 acres||£2.35||Marquess of Bute||Lewis Jenkins|
|Tir Phil||44 acres||£1.60||Lord Dynevor||Henry Harris|
|Tyledu||113 acres||£4.07||Susan Williams||Edward Williams|
|Brithdir ucha||156 acres||£8.35||Susan Williams||Edward Williams|
|Brithdir isha||115 acres||£5.70||Susan Williams||Edward Williams|
|Troed Rhiw Jestyn||94 acres||£3.60||Marquess of Bute||Thomas Morgan|
|Derry Newydd||58 acres||£1.40||Thomas Morgan||David Lewis|
|Pen-y-Fid||59 acres||£3.90||Mary James||John Richards|
|Tyr y Capel||65 acres||£5.60||Thomas Williams||Jenkin Thomas|
|Cefn Bach||128 acres||£7.25||William James||William Davies|
|Groes Faen||294 acres||£12.95||Charity||William Evans|
|Tir Evan Thomas||36 acres||£2.75||John Jones||Richard Williams|
|Cefn y Brithdir||225 acres||£13.10||George George||Thomas Rees|
|Brithdir||85 acres||£6.35||George George||Thomas Llewellyn|
|Tir Ferch Gronow||83 acres||£2.90||Marquess of Bute||William Lewis|
|Mill & land||5 acres||£0.35||Bailey Crayshaw esq.||William Lewis|
|Gwaelod y Brithdir||155 acres||£8.25||Bailey Crayshaw esq.||William Lewis|