Forum Romanum
Outlines of Roman History: Extinction of the Western Empire: Great Invasions
In this article from the 1901 textbook by William Morey, you read about the split of Rome into East and West. and the invasions of swarms of barbarians.
World History Encyclopedia
World History Encyclopedia: Alaric
Encyclopedia entry provides detail about Alaric and the sack of Rome. Includes photos, timeline and links to further reading.
The History Cat
The History Cat: The Fall of the Roman Empire
Explains some of the reasons the Roman Empire collapsed, how Roman cities and towns fell into ruins, and how barbarian groups took over with there being no strong Roman militia to keep lawlessness in check.