4 The River Liffey flows through the city and into the Irish Sea .
5 Situated at the head of a lovely bay , the city straddles the River Liffey where that stream flows eastward through a hill-ringed plain to the shores of the Irish Sea .

5 The city is named for the Gaelic phrase dubh linn , which means "black pool."
1 Irish Dubh Linn , or Norse Dyfflin ( "Black Pool" )  , also called Baile Atha Cliath ( "Town of the Ford of the Hurdle" ) , city , formally a county borough , and capital of County Dublin and of Ireland .

5 The city is named for the Gaelic phrase dubh linn , which means "black pool."
6 (The dark bog water made the "black pool" that gave the city its name . )

6 Dublin is also Ireland's chief port .
2 Located in the east-central part of the country at the head of Dublin Bay on the Irish Sea , the city is the country's chief port , centre of financial and commercial power , and seat of culture .

9 The Four Courts , the seat of Ireland's judicial branch , and the Custom House are excellent examples of Dublin's late-18th-century architecture .
52 Along the quays of the River Liffey are Dublin's finest monumental buildings , the Neoclassical masterpieces of the Custom House ( 1781-91 ) to the south and the Four Courts ( 1786-1802 ) to the north .

10 The Custom House was burned in 1921 during Ireland's war of independence , and the Four Courts was destroyed in the civil war of 1922 .
54 The Custom House was burned in 1921 during the war of independence by republicans who wished to destroy British administrative records; the Four Courts was reduced by shellfire and mines at the outbreak of civil war in June 1922 .

13 The English , who once ruled Ireland , used the castle as their headquarters until 1922 .
22 The castle , the seat of British authority in Ireland until 1922 , is now used for ceremonial occasions , especially the inauguration of the republic's presidents , who now reside at Aras an Uachtarain ( "The President's House," formerly the viceroy's lodge ) in Phoenix Park .

15 Near the castle are Christ Church and Saint Patrick's , two Protestant cathedrals .
23 Close to the castle a Viking king of Dublin built Christ Church Cathedral ( c .

16 Christ Church was first built during Dublin's earliest days , when the city was a Viking settlement ( between the 9th and 12th centuries) .
23 Close to the castle a Viking king of Dublin built Christ Church Cathedral ( c .

18 Saint Patrick's Cathedral is Ireland's largest church .
29 Christ Church is the cathedral for the Protestant diocese of Dublin and Glendalough , whereas St . Patrick's , also Protestant , is the national cathedral .

18 Saint Patrick's Cathedral is Ireland's largest church .
30 Both have been Church of Ireland ( Anglican ) churches since the Reformation .

21 The country's two houses of Parliament meet in Leinster House , an 18th-century mansion .
42 Leinster House is now the seat of the Irish Parliament .

21 The country's two houses of Parliament meet in Leinster House , an 18th-century mansion .
99 The two houses of the Irish Parliament , the Dail and the Seanad ( Senate ) , meet at Leinster House in the centre of the city .

22 On either side of it are twin Victorian buildings , built in the late 19th century .
43 Twin Victorian buildings , which were constructed on either side of Leinster House in the 1880s , contain the National Library and National Museum of Ireland .

23 They house the National Library and National Museum of Ireland .
43 Twin Victorian buildings , which were constructed on either side of Leinster House in the 1880s , contain the National Library and National Museum of Ireland .

24 Just to the east is Merrion Square , and Fitzwilliam Square is to the south .
44 Merrion Square , immediately to the east , and Fitzwilliam Square , to the south , are two of the great 18th-century squares .

25 Saint Stephen's Green is the largest of the city's squares .
45 The oldest and largest of the city's squares is St . Stephen's Green , which was recorded in 1224 as common grazing land .

26 Dublin's Phoenix Park is one of the world's great city parks .
73 Dublin's Phoenix Park is one of the world's great city parks; it covers nearly 30 square miles ( 80 square kilometres ) on the north bank of the Liffey .

26 Dublin's Phoenix Park is one of the world's great city parks .
129 Phoenix Park encompasses one of Dublin's three racecourses .

27 It covers nearly 1750 acres ( 700 hectares ) on the north bank of the Liffey .
73 Dublin's Phoenix Park is one of the world's great city parks; it covers nearly 30 square miles ( 80 square kilometres ) on the north bank of the Liffey .

28 In addition to a castle , lakes , and gardens , the park also has a zoo that is famous for breeding lions .
75 Its zoo , celebrated for lion breeding , opened in 1831 .

29 Trinity College was founded in 1592 and is Ireland's oldest university .
49 It emerges onto College Green between Trinity College and the 1729 Parliament House , which has since become the headquarters of the Bank of Ireland .

29 Trinity College was founded in 1592 and is Ireland's oldest university .
50 The University of Dublin ( Trinity College ) is Ireland's oldest university , founded in 1592 .

29 Trinity College was founded in 1592 and is Ireland's oldest university .
108 The oldest of Dublin's universities is Trinity College ( 1592 ) , the only college in the University of Dublin .

32 The National Theatre , which consists of the famous Abbey Theatre and the Peacock Theatre , opened in Dublin early in the 20th century .
116 Early in the 20th century the cultural renaissance gained strong momentum in Dublin with the opening of the famous Abbey Theatre , an enterprise associated particularly with the poet William Butler Yeats and the playwrights John Millington Synge and Lady Gregory .

33 It was founded in part by the poet and playwright William Butler Yeats .
116 Early in the 20th century the cultural renaissance gained strong momentum in Dublin with the opening of the famous Abbey Theatre , an enterprise associated particularly with the poet William Butler Yeats and the playwrights John Millington Synge and Lady Gregory .

35 The old theater burned down in the early 1950s , and a new one opened in 1966 .
118 The old theatre burned down in the early 1950s , and with government help a new theatre was opened in 1966 housing both the main Abbey stage and the smaller , experimental Peacock Theatre .

39 As the financial center of Ireland , Dublin is the headquarters for the Irish Stock Exchange as well as many banks .
89 Dublin is the headquarters for Ireland's chief financial and commercial institutions .

45 The first known settlement , however , was made by the Vikings in the 9th century AD .
137 The Vikings , or Norsemen , came in the 9th century ( c .

46 They fought off most attacks from local Irish groups , and their settlement prospered until 1170 .
141 The Viking invaders beat off most Irish attacks until 1014 , when they were defeated at the Battle of Clontarf on the north shore of the bay .

54 During the 18th century , economic success led to further growth .
157 In the course of the 18th century , economic prosperity led to the development of Georgian Dublin .

55 New bridges were put up over the Liffey , and new suburbs arose outside of the city .
158 Development spread beyond the old medieval walls; more bridges were erected over the Liffey; and splendid new suburbs arose to the north and east .

57 In 1801 the Act of Union between England and Ireland created the United Kingdom of Great Britain and ended the Irish Parliament .
168 In 1801 the Act of Union between England and Ireland abolished the Irish Parliament and drastically reduced Dublin's status .

58 This greatly reduced Dublin's importance , and the city fell into a decline .
170 The city fell into a decline from which it recovered only 150 years later .

60 Catholic schools and universities were built , and the city elected a Catholic mayor .
176 For the first time in 200 years Roman Catholic churches and schools were built , and in 1854 the Catholic University of Ireland ( now University College Dublin ) opened on St . Stephen's Green , with John Henry Newman as rector .

65 The Irish Free State was finally declared in 1921 .
197 A treaty was concluded in 1921 establishing the Irish Free State , but an antitreaty contingent of the republican army protested and took possession of the Four Courts building .

66 However , because there were people who were still loyal to England , the fighting continued until the early 1930s .
201 Political assassinations and armed raids continued until the early 1930s , and hostilities remained a marked feature of Dublin life .

68 After World War II ( 1939-45 ) , Dublin began again to spread into the surrounding countryside , and more suburbs developed .
210 After the war , as shortages eased , the city began again to spread into the surrounding countryside , and more suburbs took shape .