Battle of Pylos The naval Battle of Pylos took place in 425 BC during the Peloponnesian War at the peninsula of Pylos , on the present - day Bay of Navarino in Messenia , and was an Athenian victory over Sparta . An Athenian fleet had been driven ashore at Pylos by a storm , and , at the instigation of Demosthenes , the Athenian soldiers fortified the peninsula , and a small force was left there when the fleet departed again . The establishment of an Athenian garrison in Spartan territory frightened the Spartan leadership , and the Spartan army , which had been ravaging Attica under the command of Agis , ended their expedition ( the expedition only lasted 15 days ) and marched home , and the Spartan fleet at Corcyra sailed to Pylos . Demosthenes had five trireme s and their complements of soldiers as a garrison , and was reinforced by 40 hoplite s from a Messenian ship that happened to stop at Pylos . In total , Demosthenes probably had about 600 men , only 90 of which were hoplites . He sent two of his trireme s to intercept the Athenian fleet and inform Sophocles and Eurymedon of his danger . The Spartans , meanwhile , had 43 triremes and a large land army . Finding himself thus outnumbered , Demosthenes pulled his remaining three trireme s up on land and armed their crews with whatever weapons were at hand . He placed the largest part of his force at the strongly fortified point facing the land . Demosthenes then hand picked 60 hoplites and a few archers and brought them to the point where he anticipated the Spartans would launch their amphibious assault . Demosthenes expected that the Spartans would hit the southwest corner of the peninsula where the defensive wall was the weakest and the land was most suitable for a landing . The Spartans attacked where Demosthenes had expected , and the Athenians were faced with simultaneous assaults from land and sea . The Athenians held off the Spartans for a day and a half , however , causing the Spartans to cease their attempts to storm Pylos and instead settled in for a siege . While the Spartans ' siege preparations were underway , the Athenian fleet , 50 triremes strong arrived from Zacynthus . The Spartans failed to blockade the entrance of the harbor , so the Athenians were able to sail in and catch the Spartans unprepared ; the Spartan fleet was decisively defeated , and the Athenians gained control of the harbor . In doing so , they trapped 420 Spartan hoplites on the island of Sphacteria , off of Pylos . 120 of these were from the Spartiate class , and their peril threw the Spartan government into a panic . Members of the government were dispatched to the scene , and negotiated an armistice on the spot ; the entire Spartan fleet was surrendered to the Athenians as a guarantee for Spartan good conduct , and ambassadors were sent to Athens to seek a permanent peace . When these negotiations failed , the Athenians retained possession of the Spartan ships on a pretext , and settled in to besiege the hoplites on Sphacteria ; eventually , in the Battle of Sphacteria , those hoplites were captured and taken as hostages to Athens . Pylos remained in Athenian hands , and was used as a base for raids into Spartan territory and as a refuge for fleeing Spartan Helot s . Prelude . In the summer of 425 BC , an Athenian fleet commanded by Eurymedon and Sophocles , with Demosthenes aboard as an advisor , sailed from Athens to campaign in Sicily and assist Athens ' democratic allies at Corcyra . Demosthenes held no official position at the time , but was a strategos - elect for the Hellenic year that would begin in midsummer 425 , and the two generals had been instructed to allow him to use the fleet around the Peloponnese if he wished . Once the fleet was at sea , Demosthenes revealed his plan , which he had previously kept secret ; he wished to land at and fortify Pylos , which he believed to be a particularly promising site for a forward outpost . ( Pylos was a good distance from Sparta by march , and commanded an excellent harbor in the Bay of Navarino . ) . The generals rejected this plan , but Demosthenes caught a stroke of luck when a storm blew and drove the fleet to the shore at Pylos . Even then the generals refused to order the fortification of the promontory , and Demosthenes was similarly rebuffed when he attempted to appeal directly to the troops and subordinate commanders ; only when the boredom of waiting out the storm overcame the Athenians did they set to work building fortifications . Once they began , however , the Athenians worked hard and quickly , and the promontory was fortified and defensible within a few days . The fleet sailed off towards Corcyra , where a Spartan fleet of 60 ships was operating , leaving Demosthenes with five ships and their complements of sailors and soldiers to defend the new fort . The Spartan government was initially unconcerned with the Athenians ' presence at Pylos , assuming that they would soon depart . Once it became clear , however , that Demosthenes and his men intended to hold the site , the king Agis , who was at the head of an army ravaging Attica , turned for home , cutting his invasion short after only 15 days in Athenian territory . Once he reached home , Spartan forces immediately moved towards Pylos , the fleet at Corcyra was ordered to sail there immediately , and a summons was sent out calling allied states around the Peloponnese to send troops . The Spartan fleet managed to slip past the Athenian fleet at Zacynthus , but Demosthenes anticipated its arrival and dispatched two of his triremes to inform the Athenian fleet of Pylos ' plight ; that fleet set out for Pylos as soon as it received the news . Pylos , meanwhile , had been reinforced by the arrival of a privateer with a cargo of arms , which were distributed to the sailors , and by a Messenian pinnace , which brought 40 more hoplite s to defend the peninsula . ( Donald Kagan has asserted that these apparently fortuitous arrivals must have been the result of planning by Demosthenes . ) To meet the imminent Spartan attack , Demosthenes divided his force , placing most of his men at the point where the promontory touched the mainland , while he with 60 hoplites and a few archers waited at the point facing out to sea where the Athenian wall was weakest . When the Spartan fleet arrived , the Spartans prepared to blockade the entrance to the harbor by placing hoplites on the island of Sphacteria , which was in the middle of the entrance , and planned to place ships in the gaps on either side of that island when the Athenian fleet arrived . Battle . The Spartans assaulted the Athenian fortifications on Pylos from both land and sea . The sea attack came exactly where Demosthenes had expected it would , and he was thus in place to meet it with his men . The landing was difficult at the point of attack , so only a few of the 43 triremes were able to approach the beach at a time . The Spartan captains , following the example of Brasidas , drove their ships into the rocky shore to give their men a chance to disembark and drive the Athenians back , but the defenders refused to give , and repeated waves of attacks failed to break them . The tactic of trying to land troops on a beach facing stiff hoplite resistance was known to be notoriously difficult during this era . These attacks continued for an entire day and then part of the next , but after that the Spartans resigned themselves to a siege and dispatched several ships to bring wood for building siege engines . On the day after the cessation of attacks , however , the Athenian fleet arrived from Zacynthus . It was too late that day to attack , so the Athenians spent the night on a nearby island , hoping to draw the Spartans out into the open sea to battle . The Spartans refused to take this bait , but the next morning the Athenians sailed in both entrances to the harbor , which the Spartans had failed to block , and quickly routed the Spartan fleet ( Donald Kagan has suggested that the Spartans ' failure to blockade the entrances indicates that they could not do so , and that their plan was thus fatally flawed from the outset ) . Pursuit was limited by the size of the harbor , but the Athenians captured some triremes at sea and then landed to attempt to seize the Spartan ships once they reached land . A fierce fight ensued , in which the Athenians were eventually unable to seize more than a few ships , withdrawing after heavy casualties had been suffered by both sides . At the end of the battle , the Athenians controlled the harbor , and were able to sail freely around the island of Sphacteria ; they guarded the island closely , ensuring that the hoplites trapped there were unable to escape . Aftermath . News of the crisis at Pylos shocked the government of Sparta , and members of the government were immediately dispatched to the scene to negotiate an armistice . This reaction to the potential capture of a mere 420 soldiers may seem extreme , but is explained by the fact that the 120 Spartiate s on the island composed probably one tenth of that elite class , on which the Spartan government was based . The Spartan negotiators met with the Athenian generals at Pylos and quickly arranged an immediate cessation of hostilities . The Spartans were permitted to take food to the men on the island , and sent an embassy to Athens immediately to negotiate for a more permanent peace ; all the Spartan ships , meanwhile , were surrendered to the Athenians as security for Spartan good conduct . When the negotiators reached Athens , they made a speech to the Athenian assembly in which they argued that the Athenians should take advantage of the opportunity they had to make peace . The Spartans , they claimed , had suffered a misfortune not through incapacity or overreaching , but through mere bad luck ; the Athenians should seize this opportunity to have peace with them on good terms . This proposal , however , met with derision from the Athenian statesman Cleon ; he demanded far harsher terms , which would have given Athens control over Megara and compelled Sparta to abandon several important allies . In his speech , he recalled the concessions Athens had been forced to make in the Thirty Years ' Peace of 445 BC , when the Athenians had been at a similar momentary disadvantage . Cleon ' s terms , Donald Kagan has argued , represented a recognition that the Athenians had little to gain from a peace which surrendered the advantage they had just won without impairing the Spartans ' ability to make war , while they might secure far better terms in the future by pressing their advantage . When the Spartans asked to discuss these proposals in private , Cleon demanded that they say whatever they had to say in public . By doing so , he guaranteed that the Spartans would be forced to cut off the negotiations ( since they could hardly discuss betraying their allies in public ) , hastening the moment when the Athenians would be free to move against Sphacteria . The Spartan ambassadors returned home , and the armistice at Pylos came to an end . The Athenians , alleging that the Spartans had violated the terms of the armistice by attacking their wall , refused to hand the Spartan ships back over . Both sides settled in to fight out the fate of the men on Sphacteria ; the result would be decided later at the Battle of Sphacteria .