Robert Allen (1766-1860) of Donegal County

Some 200,000 Scots settled in Ireland in the 1600s, some as part of the Plantation of Ulster in the period 1610-1625, others came throughout the century and there was a big surge in the 1690s due to famine in Scotland.

Castlefin is in the Barony of Raphoe and the Muster Rolls for Raphoe c 1630 list 5 or 6 Allan/Allen households there then, so the name was evidently quite well established in the area by 1630.

Most of the Scots settlers were Presbyterian though there were some Episcopalians and Catholics too. There are 2 Presbyterian churches near Castlefin. Camone has baptism records from 1834 onwards & marriages from 1846 and Donaghmore has baptisms from 1835 & marriages from 1819. Presbyterians generally didn’t bother keeping burial records and there are none listed for either of those two churches. Donaghmore Church of Ireland has baptisms from 1783, marriages from 1795 and burials from 1784 onwards. There are copies of all 3 churches records in PRONI (the public record office) in Belfast. The Church of Ireland records also have an index.

Griffiths Valuation c 1858 lists just 1 Allen household in the parish of Donaghmore. That was Elizabeth Allen who lived in the townland of Ballybun where she had plot 1 which was just over 7 acres. Elizabeth was probably a widow. Ballybun is about 2 miles south of Castlefin. There was still an Allen family there in 1901 who were Church of Ireland:

http://www.census.nationalarchives.ie/pages/1901/Donegal/Cloghard/Bally…

Donaghmore Church of Ireland has baptisms from 1783, marriages from 1795 and burials from 1784 onwards. There’s a copy (with an index) in PRONI in Belfast.

According to Wikipedia, General Walker is buried in Castlecaulfield, Co Tyrone but there is a plinth commemorating him on Derry City walls:

A Doctor of Divinity, Walker was joint Governor of Londonderry along with Robert Lundy during the Siege of Derry in 1689, and received the thanks of the House of Commons for his work.

The former Walker's Monument, which stood from 1828 to 1973

He was killed at the Battle of the Boyne on 1 July 1690 (12 July New Style), whilst going to the aid of Frederick Schomberg, 1st Duke of Schomberg, Commander-in-Chief of all Williamite forces in Ireland, who was wounded during the crossing of the river in the early part of the battle. He was originally buried at the battlefield but at the insistence of his widow, his body was later exhumed and buried inside the church at Castlecaufield, County Tyrone. His body was later rediscovered and re-interred next to that of his wife but not before a cast was taken of his skull.

The Walker Plinth on the Londonderry city walls which was completed in 1828, remains in his memory; although the column that stood on the plinth was destroyed in an IRA bomb attack in 1973.

You can read the commemorative plaque on the Wikipedia site but it doesn’t appear to name anyone else.

https://en.wikipedia.org/wiki/George_Walker_(soldier)#/media/File:Walls…

The walls around Derry are open to the public and there are guided tours around them. Perhaps a local tour guide may be able to give you more information. Martin McCrossan’s company does a very good tour of the city walls: http://derrycitytours.com