Torrhen Stark

"After Aegon and his dragons destroyed the combined armies of the Reach and the Rock at the Field of Fire, King Torrhen Stark bent the knee and swore fealty to the Targaryen dynasty in order to spare the destruction of Winterfell and his people. He was forever after known as "the King Who Knelt"."

- Robb Stark

Torrhen Stark, also known as the King Who Knelt, is an unseen character in Game of Thrones. He is deceased when the series begins and has appeared in the Complete Guide to Westeros and Histories & Lore featurettes.

Background
Torrhen Stark was the last King in the North until the secession of the North and the Riverlands in the War of the Five Kings and the coronation of Robb Stark. King Torrhen's reign coincided with the War of Conquest, in which the Andal kingdoms south of the Neck submitted one by one to Aegon the Conqueror. Torrhen amassed his army and marched to meet the Targaryen warlord but by the time he arrived, Aegon had already won the decisive Field of Fire and conquered most of the South of Westeros.

After seeing Aegon's dragons and his massive host, Torrhen realized the war was already lost.

Instead of fighting, he chose to bend the knee and surrendered his crown in order to spare his people. For his submission, Aegon named him Lord Paramount and Warden of the North. Though some Northerners sneer at Torrhen as "the king who knelt", his descendants Robb and Sansa Stark argue that Torrhen "saved thousands of lives that day" and that his critics forget they are alive today because of him.

Quotes
"My ancestor, King Torrhen Stark, marched the North down to the Trident and beheld Aegon's army, larger than Torrhen's own by half and with three dragons circling overhead. Many northern bannermen wanted to attack anyway, claiming northern valor would carry the day. Others wanted to fall back to Moat Cailin and make a stand there. But Torrhen had heard how the armies of the Rock and the Reach had burned on the Field of Fire and had seen the fires still glowing beneath the rubble of Harrenhal. He knelt and laid his ancient crown as Aegon's feet and rose as a king no more but Lord of Winterfell and Warden of the North. Some Northerners still sneer at my ancestor as "The King who Knelt", forgetting that because of Torrhen they're alive today to sneer. Their ancestors didn't leave their burned bones at the Trident and their twisted swords didn't fill Aegon's new throne."

- Sansa Stark

In the books
In the A Song of Ice and Fire novels, Torrhen Stark's story is the same. It is believed he knelt at the place where the Inn of the Kneeling Man sits at the time of the books.

Torrhen's army numbered about 30,000 men but the Targaryen army that came to meet him numbered about 45,000 - nor did this represent all of Aegon's new bannermen, just the ones directly facing him. Moreover, the Targaryens had their three huge dragons. Torrhen's bastard brother, Brandon Snow, volunteered to sneak into the Targaryen camp at night and attempt to kill all three dragons while they slept but Torrhen judged that this was impossible and that the failed attempt would only invite further retaliation from the Targaryens, so he chose to surrender instead.

Torrhen Stark's decision to kneel before Aegon Targaryen saved the North from the devastation inflicted upon the Gardeners and the Lannisters. The Conqueror not only confirmed the Starks as the rulers of the North but he also allowed them to keep their own customs: the Targaryens' laws would rule over the North, but they could keep their local custom of personally beheaded condemned men instead of delegating the task to an executioner. Queen Rhaenys Targaryen, as part of her efforts to keep the realm together after the Conquest, organized a marriage between Lord Stark's daughter and Lord Arryn. However, although Torrhen had bent the knee, his sons did not want to serve the Targaryens. It was only over their strong protests that the marriage took place and they refused to attend the marriage. The North remained in the realm so it can be assumed that Torrhen was able to prevent his sons from rising up against the Targaryens. It is unknown if Torrhen was still alive when Aegon visited Winterfell in 33 AC, during his last royal progress.