Square a1 — Queen's Corner
The dark corner square starting White's Queen's Rook and anchoring the long a1–h8 dark diagonal across the entire chessboard.
Square A1
dark square
"From the corner, the longest diagonal opens."
Tactical & Strategic Role
Home square for White's a1-rook; cornerstone of queenside castling and long-range dark-squared fianchetto diagonals.
Detailed Guide
a1 is quiet, patient, and influential. As the bottom-left corner square from White's perspective, a1 anchors the entire a1–h8 diagonal and houses White's queen's rook at game start.
Frequently Asked Questions (A1)
Is a1 a dark square in chess?
Yes, a1 is a dark square on the chessboard. Located in the lower-left corner from White's perspective, it starts the game housing White's Queen's Rook (a1-rook).
What color is the a1 square on a chessboard?
The a1 square is dark (black or dark brown). A fundamental chess rule of thumb is 'White on right' — meaning the right-hand corner square (h1 for White) must always be light, making the left-hand corner a1 dark.
Why is the a1–h8 diagonal famous in chess?
The a1–h8 diagonal is the longest dark diagonal on the chessboard. Openings like the Catalan, Dragon Sicilian, and King's Indian Defense place fianchettoed bishops on b2 or g7 to slice across this entire diagonal.