What are the similarities and differences between the tasks that were solved by the emperors

What are the similarities and differences between the tasks that were solved by the emperors of Byzantium and kings in Europe?

Similarity:

1. Fight against external aggression, for example, with the Arabs. European rulers stopped their advance in 732 at Poitiers, and in 722 the Reconquista began in northern Spain, it lasted until 1492. The Byzantines fought against the Arabs (7th century) and the Turks (from the second half of the 11th century).

2. Baptism of the barbarians. The rulers of the Franks baptized tribes in the east of modern Germany, Western Christianity came to the Saxons and Western Slavs. The Byzantines brought Christianity to the Bulgarians, Serbs, and Eastern Slavs.

Differences:

1. European kings created their kingdoms on the ruins of the Western Roman Empire in the second half of the 5th century, and the emperors of Byzantium received a ready-made state in 395, that is, the Eastern Roman Empire, or the Roman Empire, as they called themselves.

2. In Western Europe, since 1054, there was a Catholic Church, which was headed by the Pope, and in Byzantium the cathedral Orthodox Church remained.

3. Development of education. In Western Europe, universities appeared in the 11th-15th centuries in large numbers.