Republika Srpska capital Banja Luka
Republika Srpska (Serbian Cyrillic: Република Српска, pronounced [repǔblika sr̩̂pskaː] (listen); also known as Republic of Srpska) is one of the two entities of Bosnia and Herzegovina, the other being the Federation of Bosnia and Herzegovina. It is located in the north and east of the country. Its largest city and administrative centre is Banja Luka, lying on the Vrbas river.
Republika Srpska was formed in 1992 at the outset of the Bosnian War with the stated intent to safeguard the interests of the Serbs of Bosnia and Herzegovina. The war saw the expulsion of the vast majority of Croats and Bosniaks from the territory claimed by Republika Srpska and an inflow of Serbs expelled from Federation of Bosnia and Herzegovina. Following the Dayton Agreement of 1995, Republika Srpska was recognised as an entity within Bosnia and Herzegovina. Today most of Bosnia and Herzegovina's Serb population lives in Republika Srpska. 
Republika Srpska is a parliamentary-style government, with the National Assembly holding legislative power within the entity. Republika Srpska is relatively centralised, although it is split into 64 municipalities called opštine. The legislature holds 83 seats, and the current session is the tenth since its founding.Politics
According to its constitution, Republika Srpska has its own president, legislature (the 83-member unicameral National Assembly of Republika Srpska), executive government, police force, court system, customs service (under the state-level customs service), and postal service. It also has official symbols, including a coat of arms, a flag (a variant of the Serbian flag without the coat of arms displayed) and its entity anthem. The Constitutional Law on the Coat of Arms and Anthem of Republika Srpska was ruled not in concordance with the Constitution of Bosnia and Herzegovina as it states that those symbols 'represent the statehood of Republika Srpska' and are used 'in accordance with moral norms of the Serb people'. According to the Constitutional Court's decision, the Law was to be corrected by September 2006. Republika Srpska later changed its emblem.
Although the constitution names Sarajevo as the capital of Republika Srpska, the northwestern city of Banja Luka is the headquarters of most of the institutions of government, including the parliament, and is, therefore, the de facto capital. After the war, Republika Srpska retained its army, but in August 2005, the parliament consented to transfer control of Army of Republika Srpska to a state-level ministry and abolish the entity's defence ministry and army by 1 January 2006. These reforms were required by NATO as a precondition of Bosnia and Herzegovina's admission to the Partnership for Peace programme. Bosnia and Herzegovina joined the programme in December 2006.
seat of government administrative center headquarters main city principal city