The Song Empire was prosperous during Zhao Kuangyi (Emperor Taizong)'s reign despite the threats posed by the northern nomadic empires, such as the Khitan-led Liao Empire, Jurchen-led Jin Empire and Tangut-led Western Xia. In 1115, the Song aligned themselves with the Jin regime in the hope of capturing the Sixteen Prefectures. However, this alliance allowed the Jurchens to learn of the Song's military weaknesses, namely a lack of capable commanders and armies primarily composed of mercenaries and poorly trained convicts. After the fall of the Liao empire, the Jin invaded Song territory and, on 20 March 1127, captured the Song capital, Bianjing (present-day Kaifeng). The Emperors Huizong and Qinzong, along with many family members, were captured and taken to the Jin capital, Shangjing, in present-day Harbin. This event is historically known as the Jingkang Incident. Many of these nobles died during the journey to, or after arriving in, Shangjing, although some committed suicide to avoid degradation at the hands of the Jurchens.