This thesis examines the impact of Turkey-EU relations on Turkey's domestic political evolution in the 1990s and 2000s, with a focus on the evolution of the religious political parties, the changing position of the military and Turkey's new energy politics. Although Turkey-EU relations resemble non-progressive affairs to many, in reality, they are as productive as any other relations that have resulted in the expected goal. Both Turkey and the EU made significant gains from this long lasting relationship. However, this thesis focuses more on the impact of these relations on Turkey. While engaging with the EU, Turkish domestic politics underwent a major evolution especially concerning the religiously motivated political parties; they were founded on anti-Western and pro-Islamic principles. However their attempt to come to power was continuously prevented by the secular forces, most importantly the army. In 2000s, realizing the importance of Europeanisation to help avoid the military's intimidation, they became the real champions of Westernisation, contrary to their founding principles. Under Erdoğan's leadership they started the accession negotiations with the EU. While Islamic political thinking was evolving, the position of the Turkish Armed Forces, who, directly or indirectly, drove Turkish politics since the 1960s, was also changing in favour of civilian control. Thanks to the EU initiated reform programs which were implemented by the religiously rooted JDP after 2002, the Turkish army's heavy presence in civilian politics was reduced almost to zero. Again, close relations with the EU encouraged Turkey to become proactive within Eurasian energy politics. As well as the good relations with the West, Turkey also started utilizing its geostrategic positioning by trying to become the energy bridge, and perhaps energy hub, between the energy producers on its eastern borders with energy hungry Europe on its western borders.