Davidson, or 'Jimmy D' as he became affectionately known, was born in Armagh on October 23, 1942.
He was born in a house adjoining the Gaelic football grounds of St. Patrick's Academy in Armagh and for a time during his university days, Davidson played Gaelic football for Pearse Ogs - lining out with the Armagh club on a Sunday, after he had played rugby for Queen's University the previous day - but the 'ban' curtailed his Sunday outings.
Indeed, earlier this year, he admitted the ban had "helped me focus on my chosen amateur career in rugby union, enabling me to win the precious few international caps I possess."
Soon after he was born, Davidson's family had moved to England, where they set up residence in Weston-super-Mare, but he was educated 18 miles away in Bristol at St. Brendan's College, where he came under the wing of Welshman Alwyn Price who imparted his impressive rugby knowledge.
Davidson's prowess as a fledgling flanker saw him picked for the England Schoolboys at Under-15, Under-17 and Under-19 level and he also tasted senior action with Bristol RFC as a 17-year-old.
His move back home to Ulster saw him study Geography at Queen's University, with whose rugby side he played his first senior match on Irish soil. The 1960s saw Davidson's rugby career take off as he successfully trialled and made his senior debut for Ulster and played his part in the Combined Universities' 12-10 triumph over a touring South African side at Thomond Park in 1965.
He then took to lining out for Dungannon RFC and he was a key player in the Stevenson Park set-up in the 60s and 70s. His first teaching post saw him based at Royal School Dungannon, and armed with a post graduate qualification in physical education from Loughborough College, he went on to teach PE and sports psychology at Belfast's Stranmillis College.
Davidson made his Ireland debut against France at Lansdowne Road in January 25, 1969, linking with Ken Goodall and Noel Murphy in the back row. Ireland won 17-9 and blindside Davidson retained his place in the side for that season's games against England (won 17-15), Scotland (16-0) and Wales (24-11).
Davidson's international career stalled, with competition increasing for back row places, but he did win his fifth cap in January 1973 when Ireland claimed a memorable 10-10 draw with New Zealand at Lansdowne Road. His back row colleagues that day were Terry Moore and Fergus Slattery.
His sixth and final Irish cap followed was also against the All Blacks in June 1976 - called up for the injured Seamus Deering, Davidson was at number eight in an Irish back row that included Stewart McKinney and Willie Duggan. The hosts won the Wellington tie 11-3.
With his PE background, Davidson's move into coaching was inevitable and he had immediate success with a Queen's side that scooped a league and cup double.
His talents were recognised by the Ulster Branch and he took over as Ulster coach in 1983, turning their fortunes around - after a shaky start - and guiding the province to threee successive Interprovincial championships.
Arguably the highlight of Davidson's reign with Ulster was a 15-13 win over the 1984 Australian side that collected tour wins over England, Ireland, Scotland and Wales.
He succeeded Mick Doyle as Ireland coach in 1987 and went to have a three-year stint at the helm, helping the men in green to wins over Scotland (22-18, January 1988), Western Samoa (49-22, October 1988), Italy (31-15, December 1988), Wales (19-13, February 1989) and Wales (14-8, March 1990).
During that time, he handed debuts to Don Whittle, Tom Clancy, Denis McBride, Michael Moylett, John Sexton, Vinny Cunningham, Fergus Aherne, Steve Smith, Noel Mannion, Pat O'Hara, Fergus Dunlea, Philip Rainey, Nick Popplewell, Kenny Murphy, Peter Russell and Gary Halpin.
Progressive and radical, Davidson was a coach ahead of his time and brimful of ideas, particularly in the areas of conditioning, diet and strength training, and he did much to improve the athletic ability of Ireland's top-level players.
In latter years, Davidson used his rugby nous to forage a career in the media, with regular stints on BBC Northern Ireland as a match analyst for Ulster and Ireland matches, and as a respected columnist in various newspapers, including the Belfast Telegraph.
Sadly, due to his illness, he had to end his writing with the Telegraph in February. Previewing the Ireland-England match at Croke Park, Davidson wrote: "This will be my last page in a series of consecutive articles written for the Belfast Telegraph in the last six years. It will complete a compilation that I have had bound together so that my two-year-old grand daughter Alex will be able to view the match from her high chair in the grandstand."
A well-respected figure within rugby and sporting circles, Davidson was a family man first and foremost and is survived by his wife Norma, daughters Kellie and Christy and extended family.
Everyone at the IRFU and IrishRugby.ie would like to pass on their condolences to Norma and the family. Our thoughts and prayers are with you at this sad time.