A significant number of states went through decentralisation or devolution reforms over the past decades. The reforms either created new regional administrations, which were elected (e.g. the United Kingdom 1999) or introduced a popular vote in the already established region (e.g.
Greece 1994). Decentralisation reforms have a particular effect on the regional parties, which are limited by the area of their operation.
The paper will focus on the Scottish National Party and Plaid Cymru - the Party of Wales and their transformation since establishing regional institutions: Scottish Parliament and National Assembly for Wales (later Welsh Parliament). The background conditions and the main purpose leading to the establishment of both parties differed significantly and played an important role throughout their existence.
Since its establishment, the Scottish National Party has demanded Scotland's independence, while Plaid Cymru was formed mainly to protect Welsh culture and language. Both regional parties had to adapt to the new conditions and create a new strategy for the new political environment.
The paper will analyse the impact of the devolution on their political agenda, demands on the national centre and change in the internal organisation structure. Moreover, it should show how those changes have impacted electoral results at both regional and national levels.
Further comparison of the two regional parties with similar institutional backgrounds should determine the main differences in the development of the Scottish National Party and Plaid Cymru in the past two decades.