Through which parts of the Roman empire did the invaders spread? Which parts did they not enter?

To determine the parts of the Roman Empire that were invaded by outside forces and those that were not, we can rely on historical sources and certain maps or atlases that illustrate the expansion and contraction of the empire over time. Here's how you can find the answer to your question:

1. Research Historical Sources: Consult reputable historical sources like books, scholarly articles, or online encyclopedias that provide insights into the Roman Empire and its invasions. Reliable sources such as ancient accounts by historians like Livy, Tacitus, or archaeological records can help determine which regions were invaded.

2. Study Maps and Atlases: Look for historical maps or atlases specifically focused on the Roman Empire. These maps often highlight the territorial extent of the empire at different periods, including areas that were invaded by outside forces.

3. Examine Historical Events: Investigate significant historical events during the Roman Empire's decline and fall. This time period, known as the Crisis of the Third Century (235-284 CE), saw invasions and incursions into various parts of the Roman Empire.

4. Analyze Geographical Factors: Consider geographical features that might have influenced the invaders' decisions. For instance, the Roman Empire's northern borders were susceptible to invasions due to the absence of natural barriers like mountains or rivers.

When conducting your research, keep in mind that the Roman Empire underwent multiple invasions and periods of territorial loss throughout its existence. Therefore, the specific regions that were invaded might vary depending on the timeframe you are interested in.