What condition made the Byzantines vulnerable to attack by Muslim Turks

The council of Nicea
The death of Constantine
Ongoing wars with the Sassanian Persians
Invasions by Huns and Germanic peoples

Ongoing wars with the Sassanian Persians

The condition that made the Byzantines vulnerable to attack by Muslim Turks was the ongoing wars with the Sassanian Persians. The invasions by Huns and Germanic peoples did pose a threat to the Byzantines, but they were not primarily responsible for making them vulnerable to the Muslim Turks. The Council of Nicaea was a church council held in 325 AD and focused on addressing theological matters, so it was not directly related to the vulnerability of the Byzantines. The death of Constantine, while significant in the history of the Byzantine Empire, did not directly contribute to their vulnerability to the Muslim Turks.

The condition that made the Byzantines vulnerable to attacks by Muslim Turks was ongoing wars with the Sassanian Persians.

To understand this, let's break it down step by step:

1. The Byzantine Empire, also known as the Eastern Roman Empire, was engaged in frequent conflicts with the Sassanian Persian Empire. These conflicts strained the Byzantine resources, including manpower, finances, and military capabilities.

2. The Sassanian Persians were a powerful and formidable adversary for the Byzantines. Their wars often resulted in significant territorial losses for the Byzantine Empire, weakening its defenses and stretching the Byzantine military thin.

3. Due to these continuous wars with the Sassanian Persians, the Byzantines had to direct a significant portion of their resources towards defending their eastern borders. This left other frontiers, including the northern and western borders, relatively exposed and vulnerable to attacks.

4. Taking advantage of this vulnerability, various invading forces, such as the Muslim Turks, started expanding into Byzantine territories. These Muslim Turks were skilled warriors and were able to exploit the weakened Byzantine defenses to capture important cities and territories.

So, while other factors like the Council of Nicea, the death of Constantine, and invasions by Huns and Germanic peoples did have their own historical significance, it was the ongoing wars with the Sassanian Persians that made the Byzantines vulnerable to attacks by Muslim Turks.