But to return, Athens sent ten ships to support Corcyra with Orders to act only defensively. The naval battle of Sybota followed in which Corinth was on the whole victorious, the Athenians participating only at the end of the day and then merely to guard the harbor. In the dusk of evening, however, when the Corinthians were about to press home their advantage, they sighted a fresh Athenian squadron of twenty ships and, fearing that these were only the first of a larger fleet, retired bitterly angry to have missed the fruits of their victory. Thus the battle ended by leaving the Corinthians in a rage of frustration and provided the first major grievance leading to war.