Jack Charlton was renowned for his working-class toughness and outspoken personality.
But the football giant remained tight-lipped over one thing for fear of causing controversy: Northern Irish politics.
His wariness stemmed from sending a taxi driver into a rage by commenting on the death of IRA hunger striker Bobby Sands.
The incident happened when Jack, who is due to be laid to rest on Tuesday after dying aged 85 while battling blood cancer and dementia, travelled to Dublin after he was named Republic of Ireland manager.
He said in his now out-of-print memoir: "On the first occasion I was invited over to meet the Football Association of Ireland, there was an incident on the taxi journey from Dublin Airport into the city which convinced me, if I was in need of any convincing, that I shouldn't get involved in the Irish political situation.
"The Northern Ireland problems were at their height at the time, and here was I, an Englishman on my way to take up the post of manager of the Republic of Ireland team.
"We were passing under a bridge and I noticed some graffiti about Bobby Sands. I made some remark about it to the taxi driver and the fellow almost went spare.
"'There were eight guys who went on that hunger strike', he fumed, 'but do the Irish people remember or give a damn about the other seven?'
"I said to myself, 'Hell, you've made a boob here, Jack. Keep your mouth shut on subjects you know nothing about."
Jack added he prided himself on "following that pledge" throughout his time as the Republic boss.
He was so serious about sticking to it that he even refused requests to front cross-border peace initiatives.
Jack was left furious after he was accused of being an IRA sympathiser for playing the rebel song Sean South (inset) of Garryowen on the team tour bus. The track is about an IRA man who died from injuries sustained in an attack on RUC barracks in Brookeborough, Co Fermanagh, in 1957.
The choice of music led Tory MP Teddy Taylor to publicly rant that Jack should be ashamed of himself.
The football boss said Taylor's comments "upset me no end", adding in his 1997 autobiography: "I never listened closely to the words, but I vaguely understood it was a republican song which dealt with the Black and Tan period in Ireland in the 1920s.
"To me, that was unimportant. It had a stirring, singalong air, just the kind to fire up the players, and we made a point of putting it on just as we were about to enter the stadium.
"That was fine, or so we thought until the day we ill advisedly invited some journalists to join us on the coach.
"The next day there were screaming headlines in the British tabloids about Jack Charlton, the 'English traitor', playing IRA songs on the coach.
"I had a letter from a mother in England, informing me that as a former member of the British Army and an OBE to boot, it was despicable for me to associate in any way with the people who had murdered her son.
"Now, what do you say to distressed woman like that?"
Jack withdrew the song from the tour bus playlist and said he was so concerned about the row that he cancelled a book signing session he had been scheduled to hold in Belfast over fears his presence would spark a protest.
His reluctance to put himself and his Republic of Ireland players at risk extended to their powder keg 1993 World Cup qualifier clash with Northern Ireland.
On November 17 that year, Charlton's team were just one step - and one point - from qualifying for the tournament when they travelled to Windsor Park.
Standing in their way was Billy Bingham's Northern Ireland team, who had already been eliminated but were intent on derailing the Republic's party.
In the two weeks before the match there had been no paramilitary murders, but in the 18 days before that fortnight there had been 26, including the people slaughtered in the IRA's Shankill Road bomb and the UDA's 'trick or treat' massacre at the Rising Sun pub in Greysteel.
The Northern Ireland game ended 1-1, Alan McLoughlin scoring the equaliser with a volley in the 76th minute, and the Republic qualified for the World Cup.
But the game and the build-up to it took a lot out of Jack. "I was deeply apprehensive about the trip to Belfast," he said. "Even by the worst standards of the Troubles, the weeks leading up to the game were disturbing.
"At one point, there was a lobby to have the match taken out of Belfast and played elsewhere.
"The football authorities, the security chiefs, the people themselves wanted the game to be played in Windsor Park.
"They said that even if that meant surrounding the stadium with a ring of steel, they would keep it there. That was precisely what they did - and on a night which will forever live in the memory."