Viertageschlacht
Louis’ plans were based on the assumption that the Dutch fleet would be at sea in time to be able to prevent the English fleet attacking the weaker French fleet in the western English Channel. However, the Dutch could not undertake to be at sea to provide cover for Beaufort until 21 May. As a result, Beaufort, who left Toulon in April 1666 with 32 fighting ships, delayed at Lisbon for six weeks while the Four Days' Battle was fought. Duquesne, who initially had 8 and later 12 ships, was ordered to join Beaufort at Lisbon so that the combined French fleet would be less vulnerable to a possible English attack before it could join the Dutch, although the two failed to meet and Duquesne returned to Brest while Beaufort stopped at Rochfort.