Although 19 Squadron and 20 Squadron were awarded their squadron numberplates last year, the challenges of Covid and the tempo of their air defence operations had prevented them from celebrating the honour any earlier.
The Duchess of Northumberland, in her duties as Lord Lieutenant, reviewed the parade on behalf of The Queen.
Here are 19 pictures of the event thanks to Jane Coltman Photography and SAC Leah Jones.
1. Parade 7
A parade was held at Alnwick Castle to celebrate the 19 Squadron and 20 Squadron numberplates being awarded. Photo: Jane Coltman Photography
2. Parade 2
A parade was held at Alnwick Castle to celebrate the 19 Squadron and 20 Squadron numberplates being awarded. Photo: SAC Leah Jones
3. Parade 13
A parade was held at Alnwick Castle to celebrate the 19 Squadron and 20 Squadron numberplates being awarded. Photo: Jane Coltman Photography
4. Parade 4
A parade was held at Alnwick Castle to celebrate the 19 Squadron and 20 Squadron numberplates being awarded. Photo: SAC Leah Jones