Barthold Kuijken is among the most prominent musicians involved in the performance of early music on authentic instruments. He often appears in concert with his brothers Wieland, a cellist and viola da gamba player, and Sigiswald, a violinist, viol player, and conductor. Often, Paul Dombrecht joins them on oboe, with either Gustav Leonhardt or Robert Kohnen on harpsichord. Though Barthold Kuijken's flute and recorder repertory largely falls into the Baroque era, he plays works by Haydn (divertimentos and trios), Mozart (the flute quartets), Schubert (violin/flute sonatas), and other pieces from the Classical era. Kuijken teamed with Immanuel Davis in 2021 on the album La Magnifique: Flute Music for the Court of Louis XIV. Kuijken was born into a musically gifted family on March 8, 1949, in Dilbeek (near Brussels), Belgium. He is the youngest of the three Kuijken brothers and thus benefited from his older siblings' example and teaching. Barthold studied music at the Bruges Conservatory, the Brussels Royal Conservatory of Music, and the Royal Conservatory of the Hague. At the latter school, Frans Vester instructed him on flute, and Frans Brüggen on recorder. Kuijken became interested in the Baroque flute at the Brussels Conservatory and began teaching himself to play the instrument from that time. After his student years, he began regularly appearing in concert engagements with his brothers and other musicians. Eventually, the Kuijkens toured Europe, much of Asia, Australia, Israel, and the Americas. Sigiswald Kuijken founded La Petite Bande in 1972, and from around that time, Barthold began appearing as a regular member of the ensemble. By the later 20th century, he was well established on the concert scene as well as in the recording studio. Kuijken typically appears in chamber music performances, but he has devoted much time throughout his career to playing in early music ensembles such as the Parnassus Ensemble and Collegium Aureum along with the aforementioned La Petite Bande. Kuijken began conducting as well as performing in 1986, and in 2002, he became the artistic director and conductor of the Indianapolis Baroque Orchestra. Kuijken has appeared on more than 50 recordings spread across several labels, including Sony Classical, Harmonia Mundi, and EuroArts, among others. In the new century, Kuijken's recordings continued appearing frequently. Among his efforts was the 2008 Accent release French and Italian Flute Music of the 18th Century, on which he was joined by his brother Wieland and Robert Kohnen. In 2020, Barthold led the Indianapolis Baroque Orchestra on the Naxos album The Colourful Telemann, conducting and soloing on his Baroque flute. In 2021, Kuijken joined Immanuel Davis on the Naxos release La Magnifique: Flute Music for the Court of Louis XIV. He has continued to remain active in the new century in his other profession, that of flute teacher at both the Hague and Brussels Conservatories. Kuijken is also an honorary charter member of the Indyflute organization.