Donna,
James & Eleanor married in Rosemary St Presbyterian church. That’s in the centre of Belfast and is one of the oldest churches in the city. (It’s records start in 1723). It was popular with the leading families in Belfast. For example, Thomas Andrews, the builder of the Titanic attended it. Their family box pew is still there. However the addresses you have for the couple (Dunmurry and Ballylesson) are some way out of town. Dunmurry is about 6 miles south of the city centre. There are several places called Ballylesson/Ballylessan near Belfast. There are two both about 25 miles north of the city, one near Ballymena and another near Larne. There’s one near Dunmurry (actually Ballylessan) in Co. Down, again on the southern perimeter of Belfast. I suspect that's the one Eleanor came from as it’s close to Dunmurry. So I wonder what led the couple to marry in Belfast?
Q1. You ask about George’s death. Which was evidently pre 1826. Death registration didn’t start till 1864 so you won’t find a death certificate. Presbyterians generally didn't keep burial records, so the only mention of his passing might be in the papers or on a gravestone (which is presumably likely to be in the Ballylesson area).
I looked in a Newspaper site and found the mention in the Belfast Telegraph of 29.4.1927 of a Thomas Allen, farmer and teacher of Ballylessan who had died. This looks to be him in the 1911 census. Perhaps a descendant of Eleanor’s family?
http://www.census.nationalarchives.ie/pages/1911/Down/Breda/Ballylessan/247624/
It might be worth searching graveyards around Ballylessan for the Allen family. I’d start with Drumbo Presbyterian as that seems the nearest. (Presbyterians don’t use the parish system in Ireland and which church you attended was often a matter of personal preference and not always the nearest to where you lived). Drumbo’s records start in 1699, so if that’s the family church you may get Eleanor’s baptism there, and perhaps quite a bit before. There’s a copy in PRONI in Belfast.
Q2 & 3. You ask who the witnesses were. The answer is there’s no way of telling. Could be relatives or just friends. With hurried marriages they can even be passers by dragooned into attending. Not likely in this case, but the point I am making is that there were no rules about who they should be nor was any record kept of their relationship to the couple, if any. Yes they were often relatives but frequently they were just their friends. I’d guess George Allen was related to the bride and George Watson the groom’s friend. The law only required 2 witnesses but you do sometimes see 3 especially if one is a child. There’s no minimum age at which you can be a witness but most Ministers advise an extra witness if one is particularly young.
Q4 No idea what MGR is. I think you would need to see the original register to try and answer that. It could be a mistranscription. It’s not something I have seen before in a Presbyterian record. (In a Catholic context MGR is Monsignor, but the Presbyterian church doesn’t have any ranks other than Minister, so it doesn’t mean that here).
Q5. I think the reference to the marriage taking place at the request of Mrs Montgomery of the Institution was because neither bride nor groom normally attended that church, and so the Minister was not obliged to perform their marriage. Mrs Montgomery has approached the Minister and asked him to conduct the service for some reason or other. Normally it would take place at the bride’s church (which could be Drumbo Presbyterian) but somebody wanted it in Belfast.
The Institution will be the Royal Belfast Academical Institution. A top school founded in the early 1800s which is still functioning today. Known informally today as “Inst.” The English Master from 1817 onwards was a Rev Henry Montgomery, so I’d guess that Mrs Montgomery was his wife.
http://rbai.org.uk
Rev Montgomery was a leading thinker and theologian of his time, and now has a commemorative blue plaque at Dunmurry Non Subscribing Presbyterian church:
https://www.newsletter.co.uk/news/blue-plaque-for-liberal-presbyterian-minister-at-dunmurry-1-7124244
(Non Subscribing Presbyterians are sometimes also known as Unitarians. They don’t believe in the Trinity, believing instead there is just a single unified entity - God. Hence the term Unitarian.)
It’s just a few hundred yards from Rosemary St Presbyterian church to Inst. So one of the families probably had some connection with the school. I don’t think it was an arranged marriage etc, nor was Eleanor necessarily pregnant nor being held in an “institution.” Possibly just someone pulling strings to get the marriage held there for their own reasons which we may not easily find out at this distance.
