Bill Brett’s latest book, “Boston, Irish,” is literally a labor of love, a work that offers an evocative and deeply layered examination of the city’s unique Irish history and heritage, from the high and mighty to those whose impact upon the community has been quieter but no less important. The cornerstone, of course, is Brett’s photographic treasure trove of the Irish and Irish Americans his camera lens has captured over his five decades as an award-winning photojournalist at the Boston Globe (his 50th anniversary with the newspaper was in June 2014). With Carol Beggy’s incisive, keenly hewn prose accompanying the book’s 262 photographs, “Boston, Irish” is a work that belongs not only in the hands of anyone with even a passing interest in the city’s rich Irish tapestry, but also in those of anyone with an interest in the history of Irish America and Ireland itself. Brett has dedicated the book to his late mother, Mary Ann Brett, an Irish immigrant whose devotion to her family and her faith were the bedrock of the Brett family’s success. Her family’s saga both on the “old sod” and in Boston (Dorchester, in the Bretts’ case) will ring familiar for countless readers of Boston Irish. Recently, Bill Brett talked with the Reporter about the book. Q. Do you consider “Boston, Irish” your most personal book to date? A. No question about it. I’d been thinking about doing this for a long time, but the time now felt right. Q. Why did it seem so timely at this particular juncture? A. In large part because the city of Boston – along with the region – is changing so much and so fast. The Boston Irish have come so far from the time of “no Irish need apply” and have made such a deep impact here. So many have been so successful in politics, business, everything. I began to go through my files and realized that along with the Kennedys and other big names, there were also so many other Boston, Irish – nuns, priests, social workers, and the like – who have and continue to give back so much to the community. I wanted to present the ones I’ve met and photographed over the years in one place. Q. In doing so, you’ve gone farther back into the city’s past than in your previous books. A. Yes, and that’s one of the key points of the book, to show that while so much has changed for the Boston Irish and right now things seems to be changing faster, it was not an overnight process. The road was long, hard, and full of suffering for so many, but the thing is that the Irish here did overcome so much. Today, there are newer immigrant groups here who are on that road, and I believe that not only have the Boston, Irish shown a blueprint for immigrant success, but they also have a duty to help out those trying to make their way. So many of the people in the new book are doing exactly that, whether they’re successful business people, clerics, philanthropists, politicians, restaurateurs, chaplains, cops, firefighters, you name it. It is time for the Boston, Irish to give back – actually, they are giving back, so I mean it’s time for them to continue giving back. I believe it’s an obligation. Q. For you, that sense of striving and giving back were imbued in you and your siblings from your mother? A. No question about that. In many ways, it’s very similar to Marty Walsh’s story. Simply put, without my mother, we wouldn’t have made it. She barely made it out of Ireland herself ahead of British arrest. Her brother was an IRA soldier in the Irish civil war, and she delivered messages as a courier for them. Q. This is probably an impossible question to answer, but do any of the photos have special resonance for you? A. The one of the O’Neill family, Sara and Diarmuid and the four Ethiopian orphans they adopted [Rahel, 7; Bezawit, 10; Selamawit, 8; and Andualem, 5] is so moving. It is something that never would have happened here 25 years ago and shows how much has changed for the Boston Irish, and because of the Boston, Irish. The photo shows how America really is the land of opportunity. I also like the one of Father Daniel J. Mahoney – the firefighters’ chaplain in every sense of the word, revered by the department. As pastor of St. Francis de Sales Church in Charlestown, Father Dan has also served the community with love, humility, and dedication. He’s a priest’s priest. Q. If there is one theme or idea or even several that you would like the reader to take away from Boston, Irish, what would it, or they, be? A. I think that the message is that for today’s new immigrants and those who come next, the “Boston, Irish” can show the way forward by example. Also, that it is the duty of the Boston Irish to help the next wave of immigrants.