The most common and most likely answer to this crossword clue is the 6 letter word REEVES
I've seen this crossword clue in The Guardian
R
E
E
V
E
S
More clues leading to the result REEVES
- Old magistrates pause briefly when first woman enters
- Local officials, historically, turn up on drugs
- Queen turned up days before royal agents, historically
- Country singer gets about, with woman and son providing backing
- Old magistrates, very English, laid into Welshman?
- Severe upset passes through any hole
- Town officials' female birds
Buddy explains!

The straight part
We know that "royal agents, historically" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case royal agents, historically = reeves.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 REEVES mean?
REEVES noun- Any of several local officials, with varying responsibilities.
- The president of a township or municipal district council.
- The holder of a proposed but unadopted commissioned rank of the Royal Air Force, equivalent to wing commander.
- A female of the species Philomachus pugnax, a highly gregarious, medium-sized wading bird of Eurasia; the male is a ruff.