In 1556, Queen Mary signed off on the first organized English plantation in Ireland. The county was carved out of the O'More clan's territories - Loígis (Leix), Slewmarge, Irry, and a portion of Glimnaliry - and renamed Queen's County in her honor. The plan was straightforward: dispossess the O'Mores, who had been raiding the English Pale, and replant the land with loyal English colonists. The plan did not work. Thomas Radclyffe, 3rd Earl of Sussex, ran the operation and found himself in a long, expensive guerrilla war. Most historians now count the first plantation as a failure. The second, after the Nine Years' War in 1607, did better. By the 1690s, Mountmellick had a Quaker community led by William Edmundson, and Portarlington had taken in Huguenot refugees who had fought for William of Orange. The countryside settled into a calm that lasted, with intervals, until the famine arrived.

When the Great Famine reached Laois between 1845 and 1849, the county's workhouses could not cope. By the time a new workhouse opened at Donaghmore in 1853, many of the poorest had already died or emigrated. The Irish language had still been spoken across the county as late as the 1870s; the famine accelerated its collapse into English. The disused railway stations at Mountmellick and Abbeyleix - the line ran from Kilkenny city through Abbeyleix and Portlaoise and dead-ended at Mountmellick - tell another quieter loss. Both stopped in the 1960s. The station houses are private homes today. Most of the major Anglo-Irish big houses still stand: Emo Court, Castle Durrow, Heywood House, Ballyfin. The Cootes and the Wellesley-Poles and the Adairs left their architecture behind. The economy that built it did not.

Peter Lalor, born in Tenakill in 1827, sailed to Australia as a young man and ended up leading the Eureka Stockade miners' revolt at Ballarat, Victoria - the most famous armed uprising in Australian history. His brother James Fintan Lalor was a Young Irelander writer who died young in 1849. John George Adair, born in Bellegrove in 1823, built Glenveagh Castle in Donegal and financed the JA Ranch on the Texas Panhandle. William Russell Grace, born in Riverstown in 1832, became the first Catholic mayor of New York in 1880. William Cosby, born in Stradbally, served as governor of New York from 1732 to 1736. Kivas Tully, born in Queen's County in 1820, designed Toronto's Trinity College and the city's Custom House. The names of small Laois townlands have left tracks on three continents.

Two pieces of older geology define the county. The Rock of Dunamase rises east of Portlaoise, a 150-foot limestone outcrop crowned with the ruined castle of Diarmait Mac Murchada - the king of Leinster whose marriage of his daughter Aoife to Strongbow in 1170 began the Norman invasion of Ireland. The Vikings had sacked Dunamase in 845. The English Confederates blew it up in 1650 with gunpowder to keep the Cromwellians from using it. The other landmark is the Slieve Bloom Mountains in the west - rolling, blanket-bog uplands shared with County Offaly, the lowest of Ireland's mountain ranges but the source of the River Barrow that drains east across the county. Most of the high ground is forest now. The walking trails are quiet. Laois does not advertise itself the way the coastal counties do; it has the bog, the rivers, the round tower at Timahoe, and a hundred kilometers of midland sky.

Today most travellers experience Laois at speed, on the M7 motorway between Dublin and Limerick or the M8 to Cork. Both pass directly through the county; the Abbeyleix and Mountrath bypasses opened in 2010, ending the legendary thirty-minute traffic jams that used to define an Irish road trip. Portlaoise, the county town, sits at the junction. The population has grown rapidly - 58,774 in 2002, 84,697 by 2016, driven by commuters who can reach Dublin in an hour. Electric Picnic, one of Ireland's biggest music festivals, fills Stradbally Hall each September. The National Ploughing Championships, the largest outdoor agricultural event in Europe, returns regularly to the county. Laois remains what it has long been: an inland county, doubly landlocked, productive, modest, content to be a place that other people are crossing on their way somewhere else.