Japan had intervened in 662 on Baekje’s behalf, but sees its land sea forces defeated and its fleet destroyed in 663 by the Chinese navy in the Battle of Baekgang.

The Daming Palace in Chang'an becomes the government seat and royal residence of Emperor Gaozong.

Muslim rule has expanded to Khorasan; garrison cities are founded at Merv and …

with the scattered Italian possessions remain securely in the fold of the Empire.

Emperor Constans travels westward, passing through northern Italy to Rome, then …

…settles at Syracuse in Sicily, where he undertakes operations against the Lombards.

A brief outbreak of plague hits Britain in 663.

Silla emerges victorious in 668.

It is from this famous date that South Korean historians speak of a unified Korea.

The period of the Three Kingdoms thus ends, but not before all of them had come under the long-term sway of Chinese civilization by introducing Chinese statecraft, Buddhist and Confucian philosophy, Confucian practices of educating the young, and the Chinese written language (Koreans adapt the characters to their own language through a system known as idu).

The Three Kingdoms had also introduced Buddhism, the various rulers seeing, in a body of believers devoted to Buddha but serving one king, a valuable political device for unity.

Artists from Goguryeo and Baekje perfect a mural art found on the walls of tombs and take it to Japan where it deeply influences Japan's temple and burial art.

Indeed, many Korean historians will come to believe that the wall murals in royal tombs in Japan indicate that the imperial house lineage may have Korean origins.

A succession dispute in Japan breaks out in 672 following the death of Emperor Tenji.

The name refers to the jinshin or ninth year of the sixty-year Jikkan Jinishi calendrical cycle, corresponding to the Western year 673.

Tenji had originally designated his brother, Prince Oama as his successor, but later changes his mind in favor of his son Prince Otomo, who takes the throne as Emperor,

Otama reigns for less than a year during the course of the violence that erupts as a result of factional rivalries before taking his own life.

His uncle Oama succeeds to the throne as the Emperor Temmu.

East Central Europe (664–675 CE): Continued Regional Fragmentation, Emergence of Proto-States, and Avar Reconsolidation

Between 664 and 675 CE, East Central Europe—encompassing Poland, Czechia, Slovakia, Hungary, and those portions of Germany and Austria lying east of 10°E and north of a line stretching from roughly 48.2°N at 10°E southeastward to the Austro-Slovenian border near 46.7°N, 15.4°E—continued to witness profound political and cultural transformations resulting from the collapse of earlier federations. Following the dissolution of Samo’s Kingdom and the fragmentation of Old Great Bulgaria, smaller, decentralized tribal polities began solidifying into early proto-states in Bohemia and Moravia. Concurrently, the Avars sought to recover some lost influence by carefully re-consolidating their authority within a more limited area of the Carpathian Basin. In Thuringia, sustained autonomy under Radulf’s successors highlighted persistent Merovingian royal weakness, demonstrating the continued transition toward powerful regional aristocracies.

Political and Military Developments

Emergence of Early Proto-States in Bohemia and Moravia

• Following the earlier collapse of Samo’s unified Slavic federation, distinct regional tribal leaders in Bohemia and Moravia increasingly solidified their power, laying the foundations for the future principalities of the Czechs and the Moravians.

• These early proto-states developed stronger localized political and military institutions, effectively maintaining autonomy against weakened external powers.

Ongoing Fragmentation and Migration of the Bulgars

• After Old Great Bulgaria’s collapse, multiple Turkic-speaking Bulgar groups continued migrating, especially into southeastern Europe. The most significant group, led by Asparuh, moved south across the Danube into the Balkans during this period, where they would eventually establish a long-lasting Bulgarian state in subsequent decades, becoming heavily Slavicized over time.

Thuringian Autonomy Under Radulf’s Successors

• Thuringia continued enjoying practical independence from weakened Frankish kings, who failed repeatedly to reassert central authority. After Radulf’s death (mid-7th century), Thuringian dukes retained substantial autonomy, highlighting Merovingian royal impotence during the continuing era of rois fainéants.

Avar Reconsolidation Efforts

• The Avar Khaganate, diminished by earlier upheavals, engaged in cautious reconsolidation, reasserting political control and re-stabilizing authority within a reduced Carpathian Basin territory.

Economic and Technological Developments

Sustained Regional Trade and Economic Integration

• Economic integration persisted despite political fragmentation, with continued robust trading relationships among Bavarian, Thuringian, Avar, proto-state Slavic, Frankish, and Byzantine territories. Goods included agricultural produce, ironware, luxury textiles, and crafted products.

Fortification and Defensive Innovations

• Growing regional stability and consolidation of localized political entities fostered continued fortification development, including fortified settlements, earthworks, and hillforts designed to secure emerging proto-states from external threats.

Cultural and Artistic Developments

Development of Distinct Regional Slavic Identities

• Bohemia and Moravia increasingly developed separate cultural identities reflected archaeologically through distinct ceramics, jewelry, settlement designs, and burial practices, laying clear foundations for medieval regional identities.

Bulgar Cultural Transformation and Slavicization

• The southward migration of Bulgar groups into the Balkans initiated their gradual cultural transformation, eventually resulting in their linguistic and cultural assimilation into predominantly Slavic populations.

Persistent Avar Cultural Legacy

• Avar influence persisted strongly across the region, notably in artistic traditions, metalwork, weaponry, and decorative artifacts, continuing to shape cultural interactions with neighboring Slavic and Bavarian peoples.

Settlement and Urban Development

Growth of Proto-State Settlements in Bohemia and Moravia

• Fortified settlements grew notably in Bohemia and Moravia, reflecting enhanced political stability, economic productivity, and nascent proto-state structures.

Stability of Bavarian and Thuringian Urban Centers

• Bavarian settlements, notably Regensburg, and Thuringian communities continued benefiting from economic prosperity and reduced military threats, supporting sustained population growth and urban development.

Social and Religious Developments

Emergence of Stable Regional Leadership Hierarchies

• Bohemian and Moravian societies developed increasingly stable hierarchical leadership, solidifying proto-state formations led by influential warrior elites capable of diplomatic and military coordination.

Thuringian Aristocratic Consolidation

• Thuringia maintained stable aristocratic governance structures under Radulf’s successors, reinforcing local power structures at the expense of Merovingian royal authority.

Continuation of Avar Social Structures

• Within their reduced territory, Avar societal and military hierarchy persisted strongly, enabling continued internal cohesion and external diplomatic engagement.

Long-Term Consequences and Historical Significance

The era 664–675 CE represented ongoing regional transformation in East Central Europe, characterized by the rise of early proto-state political structures in Bohemia and Moravia, the continued migrations and cultural transformation of Bulgar groups, and sustained Thuringian autonomy under weakened Merovingian royal authority. Concurrent Avar reconsolidation efforts provided stability within their remaining territories, ensuring continued cultural influence. Collectively, these developments set foundational patterns shaping future medieval political entities, cultural identities, and historical trajectories within East Central Europe.