Great Britain postage stamp year 1913 £1 pound green Seahorse SG 403

The £1 Seahorse was issued in 1913, depicting Britannia in her chariot drawn by three rearing seahorses—a masterful design by Bertram Mackennal, engraved by J.A.C. Harrison, and printed initially by Waterlow Bros & Layton (Waterlow & Sons).

This issue is prized among philatelists for its intricate engraving and dramatic aesthetics.

Mint condition examples, especially unmounted and well-preserved, command the highest prices—often thousands of pounds depending on freshness, centering, and marginal attributes.

Used examples vary greatly: high-grade copies with desirable cancellations may fetch up to £1,250; more ordinary examples are typically in the £500–£800 range.

Catalogue values (SG at £1,800–£3,750) reflect ideal condition scenarios, and real-world prices often fall significantly below these levels unless the piece is exceptional.

If you’re assessing or considering selling:

• Evaluate centering, gum presence, color freshness, and any marginal selvage.
• Cancellation type matters—attractive or rare cancellations (e.g., early CDS, regional marks) can elevate value.
• Certification—especially for mint or high-value used items—can enhance marketability and trust.
• Auction houses and specialized dealers may deliver better outcomes than general marketplaces for high-end items.