Borommarachathirat II vs Taejo of Goryeo

Borommarachathirat II ordered the construction of Wat Ratchaburana in Ayutthaya to commemorate his two older brothers who died in a duel for the throne. The temple became a significant religious site and a symbol of royal patronage of Buddhism, featuring a prominent prang and crypt.

Borommarachathirat II led Ayutthayan forces in a successful siege of Angkor, the capital of the Khmer Empire. The city was captured and looted, leading to the Khmer abandonment of Angkor and the relocation of their capital to Phnom Penh. This event marked the decline of the Khmer Empire.

Borommarachathirat II launched a military expedition against the northern kingdom of Lanna, capturing several towns and asserting Ayutthaya's dominance in the region. The campaign resulted in a temporary tributary relationship with Lanna, expanding Ayutthaya's sphere of influence.

Wang Geon, a general under the Later Goguryeo kingdom, defeated the forces of Gyeon Hwon at Cheonju. This victory solidified his power and set the stage for the founding of the Goryeo dynasty.

Wang Geon declared himself king and founded the Goryeo dynasty, with its capital at Songak (modern Kaesong). He unified the Later Three Kingdoms (Later Goguryeo, Later Baekje, and Silla) through a combination of military conquest and diplomatic marriages.

Taejo of Goryeo completed the unification of the Later Three Kingdoms by defeating the Later Baekje kingdom. This brought the entire Korean peninsula under Goryeo rule, ending the Later Three Kingdoms period.

Taejo issued the Ten Injunctions, a set of political and cultural guidelines for his successors. These injunctions emphasized Confucian governance, Buddhist patronage, and the importance of maintaining good relations with China.