the retreat of Thijssen meant for
him a heavy financial loss, de Geer never for a moment faltered in his
purpose. Within three weeks Thijssen again put to sea with twenty-two
ships, and by skilful manoeuvring he succeeded in making his way
through the Skagerak and the Sound, and finally brought his fleet to
anchor in the Swedish harbour of Calmar. From this harbour the united
Swedo-Dutch squadrons sailed out and on October 23, between Femern and
Laaland, met the Danish fleet, and after a desperate conflict completely
defeated and destroyed it. Thus were the wealth and resources of a
private citizen of Amsterdam able to intervene decisively at a critical
moment in the struggle for supremacy in the Baltic between the two
Scandinavian powers. But it is not in the victory won by Marten Thijssen
that de Geer rendered his greatest service to Sweden. As the Swedish
historian Fryxell truly says, "all that was won by the statesmanship of
Oxenstierna, by the sword of Baner, Torstensson and Wrangel, in a
desolated Germany streaming with blood, has been already lost again; but
the benefits which Louis de Geer brought to Sweden, by the path of
peaceful industry and virtue, these still exist, and bear wholesome
fruit to a late posterity."

This expedition under Marten Thijssen, who after his victory was created
a Swedish noble and definitely entered the Swedish naval service, though
connived at by Frederick Henry and the States-General, did not express
any desire on their part to aggrandise Sweden unduly at the expense of
Denmark. If some great merchants such as Louis de Geer and Elias Trip
were exploiting the resources of Sweden, others, notably a certain
Gabriel Marcelis, had invested their capital in developing the Danish
grazing lands; and politically and commercially the question of the
Sound dues, pre-eminently a Danish question, overshadowed all others in
importance. The Dutch had no desire to give Sweden a share in the
control of the Sound; they preferred in the interests of their vast
Baltic trade to have to deal with Christian IV alone. The Swedish threat
was useful in bringing diplomatic pressure to bear on the Danish king,
but ultimately they felt confident that, if he refused to make
concessions in the matter of the dues, they could compel him to do so.
As one of their diplomatists proudly declared, "the wooden keys of the
Sound were not in the hands of King Christian, but in the wharves of
Amsterdam." In June, 1645, hi