Centuries of traditional Irish brewing were swept away in the 20th century by three multinational brewing companies, all but erasing the memory of local beer styles.  From the 1960s to the start of this century, Irish beer consisted almost entirely of session-strength blond lagers, black stouts or reddish ales.  Even the first wave of new independent breweries, founded in the 1990s, mostly emulated this range.  The most Irish of styles are the ones that diverged furthest away from their English predecessors.