The gist of R.A.F. airman's service record for no. 306731 George Hercules Allen is as follows...
Birth date: 7 January 1897
Birthplace: Town=Dublin Parish=Grange County=Dublin
Religious denomination: Presbyterian
Date of entry into R.A.F.: 9 October 1918, aged 21 at that date
Civilian occupation: farmer
Description: Height=5'4" Chest=33.5" Hair=Brown Eyes=Blue Complexion=Fresh
Transfer to R.A.F. Reserve: 11 March 1919
Person to be informed of casualties: John Allen, 9 Heaton Grove, Newcastle on Tyne Relationship=Father
I noticed a further daughter born to John Allen and Mary Ann / Marion Bell in Belfast, presumably named after John's sister Sarah Sidney (married to David Parkinson), the birth in December 1906 took place at their address, 211 York Road:
https://civilrecords.irishgenealogy.ie/churchrecords/images/birth_returns/births_1906/01722/1681292.pdfThe Belfast Street directories on the Lennon Wylie website show the following entries for York Road:
1907:
211. Allen, J., clerk 1908:
211. VacantBy 1911, what is clearly him and his family are living at 27 Orchard Road, Tranmere, Birkenhead, they are listed in the census as:
- John Allen (Head of household) a 42 year old married shipyard clerk, born Portrush, Co Antrim Ireland
- Marion Allen his 39 year old wife, married 15 years with 3 children born, all still alive, born Kingstown Co Dublin
- John Allen, 17 year old son, single, an apprentice engineer in the shipyard, born Maghera Co Derry
- Mary Allen, 13 year old daughter at school, born Belfast
- Irene Allen, 8 year old daughter at school, born Belfast
- Sarah Allen, 4 year old daughter, born Belfast
- William Allen, a boarder, 34 year old and single, a Loco Engine Driver in the shipyard, born Portrush Co Antrim
So I'm guessing that the move across the water took place 1907-1910, presumably chasing work, maybe also the driver for ending up later in Newcastle on Tyne