[6] In 1954, Flanagan also participated in his first annual Royal Ulster Academy of Arts exhibition, showing three works, two flower paintings and one landscape.
In 1960, Flanagan was appointed one of seven trustees of the newly formed Lyric Players Trust including Deborah Brown and John Hewitt, a position he was to hold for five years.
An invited artist, he showed alongside several others including Colin Middleton, Deborah Brown, Gerard Dillon and William Conor, at the inaugural exhibition in the gallery designed by the architect Robert McKinstry.
[12] In 1961, Flanagan was patronised with a one-man show at CEMA's Chicester Street Gallery of which the Belfast Telegraph's Kenneth Jamison writes:"Light is the artist's theme, its flux rain-filtered over moist fields, spilling an irregular pattern on low lough-side hills, mirrored again from the still lough's face...Always one is conscious of the infinite subtle modulations of light and colour.
The exhibition at Queen's University was organised by his wife, Sheelagh, and showed work from thirty artists, including Deborah Brown, Cherith McKinstry, William Scott and F E McWilliam.
[22] Kathleen Bridle was reunited with her two most famous students in 1973 when the Arts Council of Northern Ireland staged a touring exhibition of her works alongside Flanagan and William Scott.
[23] The wife of the Northern Irish Secretary of State Colleen Rees was the curator of a personal selection of works from Ulster Artists hosted at the Leeds Playhouse Gallery in 1976.
[25] Flanagan was part of a consortium of forty well-known Ulster names who attempted to win the Independent Television franchise for Northern Ireland in 1979.
The catalogue contained a foreword written by Seamus Heaney and a critical essay by Curator of Art at the Ulster Museum, Brian Kennedy.
[32] William Keith, director of the Wellington Tank Company, commissioned Flanagan and three of his Ulster contemporaries, Basil Blackshaw, Charles McAuley and James McIntyre to paint one picture each to be donated to the geriatric ward at Belfast City Hospital, who had cared for his dying father just a few months earlier.
[33] The 1970s saw Flanagan complete a number of prestigious commissions including one to produce a design commemorating the fiftieth anniversary of the formation of the Northern Irish state, Ulster '71, in 1970.
[2] The Arts Council of Northern Ireland funded a Flanagan portrait of Belfast feminist, trade-unionist and peace activist Saidie Patterson in 1975.
[2] In 1977, he completed a line-drawing portrait for Gael Linn's eponymous double LP by Donegal fiddler John Doherty which was released a year later.