The Sound Toll Registers constitute a record group of immense international relevance. It provides detailed information about every single ship and cargo that entered the Baltic and departed from the Baltic through the Danish straits. The Sound Toll was introduced in the 15th century. The oldest Sound Toll Register that has been kept til today is from 1497, while the series is complete from 1557 to 1857, when the Sound Toll was abolished. The Sound Toll Registers contain a wealth of information and provide a most valuable potential for research of many kinds and concerning many nations. Nowhere else can be found a record group of equivalent value when it comes to important information concerning international trade over several decades. The Sound Toll Registers are kept in the Danish National Archives.