After months of speculation, Arsenal have finally completed the signing of Sokratis Papastathopoulos from Borussia Dortmund for a reported fee worth around €19 million.The 29-year-old, who also has vast experience on the international stage having made 79 appearances for Greece, will wear the No 5 shirt at his new club. In consequence, the center-back becomes Unai Emery’s third signing of the summer after the free transfer of experienced Switzerland captain Stephan Lichsteiner and goalkeeper Bernd Leno."It is a beautiful moment and I am very happy that for the next years I will be here. Arsenal are one of the three biggest teams in the Premier League," Papastathopoulos told Arsenal's website."I'm a normal defender. I like to defend. I like that my team doesn't take goals. I like a zero in the defence and I will do everything to help to achieve this goal."Here's how Twitter reacted to the sensational news.All of us when we finally announced #SOKRATIS 😃 pic.twitter.com/Q7QCShJHA5— Arsenal FC (@Arsenal) July 2, 2018#DerPapaMachtEsGut pic.twitter.com/IWPeXH0RSt— Borussia Dortmund (@BVB) July 2, 2018Konstantinos MavropanosAlexandre LacazetteHenrikh MkhitaryanPierre Emerick Emiliano AubameyangStephan LichtsteinerSokratis PapastathopoulosGuess Arsenal took the "BIG NAME SIGNING" concept a bit literally😂😂#arsenal— Saad Asif (@SaadAsif01) July 2, 2018Wait i just realised i will have to deal with english commentators struggling to say Papastathopoulos week after week— Dαnαi✨🇮🇷🇬🇷 (@danaibalt) July 2, 2018Think #SOKRATIS Papastathopoulos will be a somewhat good signing for Arsenal. His career at Dortmund has been decent overall and will add much needed experience with PM retired and LK out for a long time. A better defender than SM and can help tutor our younger defenders. #afc— John. (@ByJohnSmith) July 2, 2018Sokratis Papastathopoulos… or Papa for short 😉 #SOKRATIS pic.twitter.com/O8RDrDYTeG— Arsenal FC (@Arsenal) July 2, 2018Arsenal sign Sokratis Papastathopoulos from Borussia Dortmund for £17.6m.Can't wait for Paul Merson to pronounce his name next season 😂 pic.twitter.com/eHWhLHzZRt— UNILAD Football (@UNILADFooty) July 2, 2018Papastathopoulos, Mkhitaryan, Aubameyang and Mavropanos in one team is a Paul Merson’s nightmare 😂— 🇺🇾 (@JessOzil) July 2, 2018Already waiting for Paul Merson to pronounce Sokratis Papastathopoulos next season. 😅 pic.twitter.com/U3ynzZP0SR— 90min (@90min_Football) July 2, 2018New Arsenal signing Sokratis Papastathopoulos looks over the moon to have joined the club pic.twitter.com/axMr2kf6Ov— ⚽️ is a Country (@FutbolsaCountry) July 2, 2018I’m looking forward to seeing Konstantinos Mavropanos and Sokratis Papastathopoulos playing together in defence with Pierre-Emerick Aubameyang and Alexandre Lacazette playing upfront for Arsenal next season. #SOKRATIS#Arsenal— 👑 DaddyMo PhD CEng 👑 (@officialdaddymo) July 2, 2018can’t wait for the English media to try to their hand at pronouncing Sokratis Papastathopoulos— Jack Grimse (@JackGrimse) July 2, 2018Good luck to the commentators when Sokratis Papastathopoulos and Konstantinos Mavropanos start as centrebacks!— Marius Jørgensen (@mariusjorg26) July 2, 2018Glad I'm not an Arsenal fan, imagine the cost of trying to get "Papastathopoulos" on the back of your jersey😂😂 pic.twitter.com/leF7zCODXv— Mark McKee (@markmckee98) July 2, 2018Sokratis Papastathopoulos24 letters Finally arsenal make a big name signing— 🔴🔴🔴 (@I22334455I) July 2, 2018We’ve got Sokratis Papastathopoulos to join Konstantinos Mavropanos.We need extra 5 mins a half if we are gonna chant their names #Arsenal— sidesey (@sidesey) July 2, 2018Fun fact: Playing 'Sokratis Papastathopoulos' in scrabble will get you more points than Arsenal in 18/19.— olivé (@Ollibreh) July 2, 2018Arsenal signings in 2018:Konstantinos MavropanosHenrikh MkhitaryanPierre-Emerick AubameyangStephan LichtsteinerSokratis PapastathopoulosPaul Merson on Soccer Saturday having to pronounce them 😂😂😂 pic.twitter.com/qB8m8JK1Bz— Football Super Tips (@FootySuperTips) July 2, 2018I hope Sokratis' tackles will be as hard as his name— Sokratis Papastathopoulos (@Ken_Murunga) July 2, 2018Arsenal now have three former Borussia Dortmund players in their current first-team squad:• Henrikh Mkhitaryan• Pierre-Emerick Aubameyang• Sokratis PapastathopoulosEx-BVB Head of Recruitment Sven Mislintat with some *big-name* signings. pic.twitter.com/6gEJwlG9A8— Squawka News (@SquawkaNews) July 2, 2018The trio are back!Henrikh MkhitaryanPierre-Emerick AubameyangSokratis Papastathopoulos pic.twitter.com/S8RT8aELYA— Fan Antics (@FanAnticsFC) July 2, 2018His name's alphabets are more than @SpursOfficial trophies😂😂😂— kadfi kader (@KaderKadfi) July 2, 2018Arsenal have signed Sokratis Papastathopoulos. Yessss I spelt that correctly. I deserve some accolades. 😂👍.— July 13th (@Kulvic) July 2, 2018Visit our Arsenal Transfer News page for all the latest Arsenal transfer rumours, updates and confirmed Arsenal Transfers.