Antiquity's map-maker, Ptolemy, produced in 150 AD the earliest map of Ireland, showing a place called Regia at the same site as King's Island.

History also records an important battle involving Cormac mac Airt in 221 and a visit by Saint Patrick in 434 to baptise an Dál gCais king, Carthann Finn.

In 812 the Vikings sailed up the Shannon and pillaged the city, burned Mungret Abbey but were forced to flee when the Irish attacked and killed many of their number.

[12] The Normans redesigned the city in the 12th century and added much of the most notable architecture, such as King John's Castle and St Mary's Cathedral.

[attribution needed] The English-born judge Luke Gernon, a resident of Limerick, wrote in 1620 that at his first sight of the city he had been taken by its "lofty buildings of marble, like the Colleges in Oxford".

The treaty offered toleration to Catholicism and full legal rights to Catholics that swore an oath of loyalty to William III and Mary II.

However, the economic downturn in the European conflicts of the French Revolution and Napoleonic eras, and following the Act of Union 1800, and the impact of the Great Irish Famine of 1848 caused much of the 19th century to be a more troubled period.

In 1942 Shannon Airport (located in County Clare, 20 km west of the city) opened for the first time offering transatlantic flights.

Limerick is the third-largest city in the Republic of Ireland (after Dublin and Cork), with a population of 102,287 in the urban area[2][22] and 104,952 in the metropolitan district, according to the 2016 CSO census.

[4][needs update] The ethnic diversity in Limerick's population, which includes a large immigrant community, saw rapid growth during the Celtic Tiger and the following decade.

[citation needed] As of the 2016 census the Polish community was one of the largest demographic groups in the Municipal District, with approximately 4,000 living and working in the area.

[28] Former well-known mayors include TDs Donogh O'Malley, Stephen Coughlan, Michael Lipper, Jim Kemmy and Jan O'Sullivan.

Newer suburban districts such as Dooradoyle, Castletroy – including the University, Gouldavoher, and Raheen were continually administered to by Limerick County Council until the merger of the two authorities in June 2014.

Met Éireann maintains a climatological weather observation station at Shannon Airport, 21 kilometres west-northwest of the city in County Clare.

Limerick natives include Pulitzer Prize-winning author Frank McCourt, and novelists Kate O'Brien, Michael Curtin, Kevin Barry and Donal Ryan.

[51] In 2020, it was announced that the Dromkeen-based Shiloh Trust was seeking planning permission to convert the former premises of Baker Place into a bible school.

Spin South West, owned by Communicorp, broadcasts to Counties Kerry, Clare, Limerick, Tipperary and southwest Laois from its studios at Landmark Buildings in the Raheen Industrial Estate.

[60] Newtown Pery was built in the late 18th century before the Act of Union and, unusually for an Irish city and unique in Limerick, is laid out on a grid plan.

Other buildings of architectural note in the city are St John's Cathedral, designed by the notable Victorian architect, Philip Charles Hardwick.

The park is dominated by the Thomas Spring Rice memorial (MP for the city 1820–1832) and has a large collection of mature deciduous and evergreen trees.

The fishing industry in Limerick, based on Clancy's Strand opposite King John's Castle and at Coonagh nearby, once employed hundreds of men.

The city centre also has a large retail district which includes a mix of more traditional type of shops as well as some modern high street stores.

Iarnród Éireann's Limerick Colbert station is the railway hub for the city and the Mid-West Region with a number of intercity and commuter rail services.

Connections to the other cities were improved with the completion of the M7 motorway in December 2010, and continuing upgrades ongoing to the N/M18 to Shannon, Ennis, Galway, and Tuam – the final section opened in September 2017.

St Michael's member and Limerick native Sam Lynch won the World Rowing Championships gold medal in the Men's Lightweight Single Sculls in 2001 and 2002.

[108] Limerick's Gaelic Grounds (Páirc na nGael), on the Ennis Road, is the county team's home venue for both sports and has a capacity of 49,000 following reconstruction in 2004.

In 1961 it hosted Ireland's biggest crowd for a sporting event outside Croke Park when over 61,000 paid to see the Munster hurling final between Tipperary and Cork.

[113][114] Two-time European champions Munster play most home matches at Thomond Park, where they held a record of being unbeaten in the Heineken Cup for 26 consecutive games until the 16–9 defeat by Leicester in January 2007.

[115] Munster recorded a famous 12–0 victory against the New Zealand All Blacks in 1978 at Thomond Park and came close a second time when the teams met in 2008, losing 18–16.

[118] Since its inception in 1991 the All-Ireland League has been dominated by Limerick City teams, with three clubs winning the competition 13 times between them: Shannon (9); Garryowen (3) and Young Munster (1).