Barcelona have a proud and rich history. The Blaugrana started off in the 19th century, building a foundation that would bring the best players from across the world to play for them. While their century-long history is full of captivating moments and exciting wins, Barcelona's most exciting era has been in the 21st century.Led by their current manager Xavi Hernandez alongside legends Andres Iniesta and Lionel Messi, the Blaugrana have had their fair share of record-breaking wins and trophies. Through much of the last two decades, Barcelona have won many major trophies, including ten La Liga and four Champions League trophies.La Masia, Barcelona's famed academy, has been integral to the club's massive success. Young players like Messi have rose through the ranks to become key players in one of the best club teams in the world. However, the Farmhouse isn't the only source of Barcelona's era of dominance in Spain and Europe.FC Barcelona@FCBarcelona📸 Leo #Messi,Making history since 2004 🐐8:10 AM · Apr 5, 2021172561612📸 Leo #Messi,Making history since 2004 🐐 https://t.co/4NFEfBwNiUThe Blaugrana have had varying degrees of success in the transfer market since the turn of the century. Many of those players have helped the club grow on and off the pitch. While there have been flops like Philippe Coutinho, some of Barcelona's signings have been brilliant and influential.So without further ado, here's a look at five such signings in the 21st century that have been influential in boosting Barcelona's success and pedigree:#5 Gerard Pique | BarcelonaFC Barcelona vs Real Madrid CF - La Liga SantanderWhile he is a La Masia graduate, Barcelona had to sign Gerard Pique from Manchester United. He had gone in search of opportunities elsewhere, which resulted in a four-year stint at Old Trafford. However, Barcelona signed the Champions League winner for €5 million in 2008.It has turned out to be one of Barcelona's best pieces of business in recent memory. That's because Pique has been a rock in the club's defence for over a decade.Alongside his star teammates, Pique has won over 25 trophies for Barcelona; he is also a World Cup and European Championship winner with Spain. He might be old now and struggling to perform like he once did. But his defensive partnership with Carles Puyol, another Barcelona legend, will always be memorable for Blaugranes.#4 Ronaldinho | Barcelona legendBarcelona vs Athletico MadridWhen PSG sold Ronaldinho to Barcelona for €30 million in 2003, some wondered whether the Brazilian was worth the price. But in his first season, the star showcased his flair, exciting dribbles and brilliant style of play.It didn't take long for the Blaugranes to fall in love with the legend, even though he spent less than six years at Barcelona.FC Barcelona@FCBarcelona👑 Ronaldinho Gaúcho 👑 Leo #Messi 🔥🔥 A lethal connection 🔥🔥 🔝🎥 ow.ly/I29F309CQtx #ForçaBarça2:30 AM · Mar 6, 20171238280👑 Ronaldinho Gaúcho 👑 Leo #Messi 🔥🔥 A lethal connection 🔥🔥 🔝🎥 ow.ly/I29F309CQtx #ForçaBarça https://t.co/9jPUNJyaf1Ronaldinho helped the Blaugrana to back-to-back La Liga titles, and also won the 2005-06 Champions League with a classic toe-poke goal against Chelsea in the Round of 16. He joined AC Milan in 2008, but Ronaldinho remains one of the best signings Barcelona have ever made.