Samuel's farewell speech, although he doesn't actually die for quite awhile. He reminds them of the covenant, and of their military victories in Judges, and laments their clamour for a king. He reminds them to keep faith, and as a sign of his power, he calls on god for a thunderstorm. The people are amazed. He warns them that if they don't obey, god will punish them.
Saul decides to attack the Philistines and gathers an army. His son Jonathan makes the first foray, killing an entire garrison. The Philistines respond, gathering 30 000 chariots and 6000 horsemen. The Battle of Hastings, in which William the Conqueror took over all of England, and which took place in 1066, involved perhaps 15 000 troops in total by the way, to put things in perspective here.
The Israelites see the formidable Philstine army, and hide. Saul is somewhere else on Samuel's orders, and Samuel is nowhere to be found. Eventually Saul gets hungry and makes a burnt offering. Samuel smells the delicious barbecue and turns up. Saul explains he didn't know what else to do, since Samuel wasn't there, but Samuel is a barbecue prima donna who won't have anyone else touching his grill, so he tells Saul that god has chosen another man to be king. Then the battle just kind of... fizzles, as the armies sort of wander off.
We then find out that the Israelites have no blacksmiths, and have to get the Philistines to sharpen all their knives for them, and in the entire Israelite army, there are only two swords: Jonathan's and Saul's. No wonder they all hid.
Jonathan decides to go on a private mission to kill Philistines. He doesn't tell his father, who is hanging out under a pomegranate tree with some of his buddies. In his very first slaughter, well, except that one in the previous chapter, which might not count because it was a 'bloodbath', Jonathan kills 20 Philistines. God shows his approval with an earthquake. Jonathan then stands back and watches as god takes over the Philistines' will and forces them to kill each other.
Saul finally figures out his son is gone and... calls for the ark of the covenant. He leads his troops over to the battle, where the Israelites among the Philistine army rejoin them. The rest of the Philistines run off, and the Israelites chase them and god finishes them off.
Now, before all this, Saul had vowed not to eat anything until all his enemies were slaughtered. The hungry men pass by a honeycomb, but don't take any, except Jonathan, who was at the back and didn't hear what his father said. The people inform him of his father's promise, and he, and the bible, very reasonably point out how much more energy he had for killing people thanks to that sugar rush.
When the Philistines are finally annihilated, the Israelites descend ravenously upon their cattle and eat the blood. Saul builds an altar and asks god what happened. God doesn't answer, so he asks the leaders to bring his troops over so he can find out what the sin was and vows to put the sinner to death, even if it was Jonathan. Roh-roh! Saul finally figures out by casting lots that Jonathan did something. Jonathan confesses to eating some honey. Saul is sorry, but that means a sacrifice. The people aren't happy and rescue Jonathan. Saul gives up his pursuit of the Philistines and everybody goes home.
But Saul is one of those incredibly annoying neighbours who isn't happy unless he's causing trouble. He makes war against all the surrounding peoples, but especially the Philistines. Eventually, he runs out of recruits and starts press-ganging people into his army.