Vladimir Lenin, the Russian revolutionary, spoke with a Dublin accent. Well, according to Roddy Connolly, son of James, who said in a 1976 Irish Times feature that Lenin, more specifically, had a “Rathmines accent”. This was due to the fact apparently that Leinin was taught English in London (c. 1902) by an “Irish tutor, who had lived in Leinster Road”. 
After this was repeated in An Irishman’s Diary by Frank McNally early last year, a letter was sent into the paper by Dalton O’Ceallaigh. In it he discussed attending, in the late 1970s, a Dublin meeting organised by the Ireland-USSR Society at which Roddy Connolly spoke about his visit to the infant Soviet Union in the early 1920s. After the speech, there was a short silent film in which Roddy was shown walking across the square in front of the Winter Palace in what was then Petrograd and conversing with Lenin.
O’Ceallaigh made the point in his letter that “there was no interpreter, so they were obviously speaking in a mutually comprehensible language”. After the film, Roddy himself stated that
After Lenin’s death, the Russians, on researching his life, believed that when he was in London (he) had placed an advertisement in the London Times to the effect of “if you help teach me English, I’ll help teach you Russian”, the person who replied being a “Mac” somebody or other was thus a Scot. But Roddy said that, on the contrary, it must have been an Irishman. 
The memoirs of Lenin’s wife Nadezhda Krupskaya offer some indirect support for Connolly’s claim:
“When we arrived in London we found we could not understand a thing, nor could anybody understand us [...] It amused Vladimir Ilyich, but at the same time put him on his mettle. He tackled English in earnest. We started going to all kinds of meetings, getting as close as we could to the speaker and carefully watching his mouth. We went fairly often to Hyde Park at the beginning. Speakers there harangue the strolling crowds on all kinds of subjects [...] We particularly liked one such speaker – he had an Irish accent, which we were better able to understand.” 
On a side note, what exactly is a Rathmines accent?
Frank McNally suggests it was forerunner to the Dart accent which came to public attention first in the early 1990s. The earliest reference to such a thing that I could find is 1908. D.J. O’Donoghue, in a recollection piece about George Bernard Shaw, spoke about how Shaw had “possessed a ‘Rathmines accent’ which he never entirely lost”. 
A jokes corner from The Irish Press in 1936 had this to say:
The Radio Correspondent of The Irish Times in 1946 suggested that the “broad or moderately broad ‘a’ sound (is) a defect characterestic of that mincing, effeminate speech known in Dublin as the Rathmines accent and in Belfast as the Malone Road accent”. 
Two years later, another explanation on the accent was given:
Many of the Radio Eireann announcers are guilty of frequent lapses into the genteel, mincing manner of speaking known as the Rathmines accent. One announcer keeps referring to Pakistan as ‘Pawkistan’, several of them talk about ‘fawther’, [for 'father'] ‘curless’ for ‘careless’, and worst of all ‘infearm’ for ‘infirm’”. 
It would seem people tried to use the ‘Rathmines accent’ to get into pubs. As illustrated by this 1942 news story:
Finally, John O’Doherty in a letter to The Irish Times early last year said that the “genteel Rathmines accent was still common when I lived there in the 1960s [...] it was also known as an “ORE and ORE” accent, as it was widely spoken in both Rathmines and Rathgar”. 
 Michael McInerney, Roddy Connolly – 60 years of political activity, The Irish Times, 08 Sep 1976.
 Dalton O’Ceallaigh, Letter to Editor, The Irish Times, Feb 15, 2011
 Nadezhda Krupskaya, Memories of Lenin (London, 1930), 65
 D.J. O’Donoghue, George Bernard Shaw – Some Recollections, The Irish Independent, 17 Feb 1908
 Radio Correspondent, Irritating mispronunciation on Radio Eireann, The Irish Times, 24 Jan 1946
 Anon, An Irishman’s Diary, The Irish Times, 13 Apr 1949
 John O’Doherty, Letter to Editor, The Irish Times, Feb 14, 2011