Ambush on the High Road

The Ambush on the High Road was an attack that took place in 407 AC, when an army of Mountain Clansmen descended upon the Valemen who were returning to the Eyrie from the tourney at Harrenhal. It was a victory for the Vale, but came at a cost - it saw the death of the future Lady of the Vale: Rowena Waynwood.

Background
Scouts along the hills of the Vale spotted the Valemen as they departed for Harrenhal, bringing word back to their leader in the mountains. The Redsmiths decided to use the opportunity to reignite their feud with the Andal lords, and spent long weeks preparing for their return.

When Osric Arryn led the returning caravan back along the high roads of the Vale, a band of clansmen lying in wait picked off his scouts and outriders. They then descended a stony slope, charging the long line of carriages and wheelhouses in several places all at once.

Engagement
The first bit of warning that any of the Valemen had was the roar of a battlecry from the top of the hill - all at once men seemed to materialize from stone, pouring down the slope as they charged.

Osric Arryn hastily formed a defense at the front of the line, though charging up the stony slope to meet their foe was all but impossible. With Dannyl Waynwood and Alester Hersy at his side, the young heir of the Eyrie fought to defend the caravan.

Further down the line, other bands of clansmen attacked - slaughtering men, women, and children wherever they could be found. Aianna Corbray, spotting one such band, led the counter-attack that would drive them off long enough for the more experienced knights to join her.

The fighting was hard and fierce, but the Andals proved victorious. With the sound of a warhorn the assault was called off, and those clansmen who yet survived pulled back and fled into the hills.

Osric ordered his men to hold their ground, refusing to give permission for a pursuit. He gathered a group of retainers and traveled down the line, checking on the various lords and ladies who had accompanied him along the road.

Amongst the nobles slain was Osric's wife, Rowena Aryrn.

Aftermath
The death of Rowena Waynwood drove Osric to summoning the Vale's banners, intending to march them into the mountains to avenge their slain and fallen. Instead, Alaric Arryn returned home to the Eyrie to find an army ready and waiting for him - the Defender of the Vale would opt to use that force to begin his advance into the Riverlands, rather than into the high hills.

Her death also made Osric a widower, freeing him to wed Princess Saera Targaryen the following year, in order to restore relations with the Crown.