They would become known as the Manchester Martyrs and every Irish schoolkid knew their names because the song that followed their hanging, God Save Ireland, became the unofficial national anthem of the country.

(It was changed to the current anthem in 1926, because the words were considered too close to the similar prayer for the monarch.)

It is tempting to give the names of the three unfortunate Fenians except that they might confuse the reader who has to put up with a veritable directory of Irish surnames in the first hundred pages of this book.

There is Jack Riley, Peter Rice, Michael Sullivan, Robert Neill, Thomas Flanagan, Willie Devine, Kelly, Magee, Neary, Slattery, Byrne, not to mention the two main characters Joseph O'Connor and Stephen Doyle.

Doyle is an American, a survivor of their civil war, sent to England to help the Fenians in their mischief.

O'Connor is a Dublin policeman and the person who gives the book its title.

He has been sent to Manchester as an alternative to being sacked for his drinking; his job is to find someone among the Irish in his new city who will tell him what the Fenians are planning.

He has plenty of names to choose from, most of them pathetically incompetent and full of boozy stage-Irish blather.

The Fenians were an oathbound and highly secret group of ruthless killers, who were much more adept than those presented here.

Mind you, the English - non-Irish surnames, thankfully - are equally hopeless and it is difficult to take either group seriously.

Just when you are getting into the story, another group of Irish are introduced: Malone, Dixon, McArdle, Devlin, O'Toole, McDonnell.

And Riley is back in the action: what was he again?

Towards the end, the story moves to New York where new characters are introduced, mercifully not all with Irish surnames, one of whom has the dubious honour of having the last chapter to himself.

The book reads like half a dozen stories, loosely connected, a bit of romance here, a lot of killing there, some history in between.

I have one gripe: although the story is set in the middle of the 19^th century, the language is strangely modern.

Were the f-words and c-words used as indiscriminately in the mid-1800s as they are today because the dialogue is the kind you would expect among the rougher elements in contemporary Dublin or Manchester?

Despite often polished prose, this is a tedious and long-winded read.