The right of investiture is the right to appoint people to ecclesiastical posts such as bishoprics. In the eleventh and twelfth centuries, a series of Popes claimed the right as their own, which had previously in practice rested in the hands of local rulers. Disputes between Henry I and the Gregorian papcy even led to Archbishop of Canterbury Anselm's exile in 1103. However, in 1107 a Concordat of London was signed that agreed a compromise. The terms of this arrangement were employed again at the Concordat of Worms in 1122, which largely brought an end to this extended dispute.
Editors. "Settlement of Investiture Dispute". The Literary Encyclopedia. First published 31 July 2012
[http://www.litencyc.com/php/stopics.php?rec=true&UID=1953, accessed 17 September 2014.]