The most common and most likely answer to this crossword clue is the 7 letter word NORMANS
I've seen this crossword clue in Financial Times
N
O
R
M
A
N
S
More clues leading to the result NORMANS
- Opera covering polar opposites? Wisdom was famously one of them
- Two points about unusual Roman invaders of Britain
- Operatic heroine partners French invaders
- Wisdom’s maybe evident in invaders crossing the Channel
- Points about unusual Roman invaders
- The invaders will come from the south. Wisdom a posteriori? On the contrary
- Invaders succeeded with right to enter Donne’s island?
- They invaded England from heart of France, breaking usual rules
- Established practices limiting an army of invaders?
- Conquerors of Poles hoisting standard on top of arsenal
Buddy explains!

The straight part
We know that "army of invaders" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case army of invaders = normans.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does NORMANS mean?
NORMANS noun- Normie
- A wooden bar, or iron pin.