Windsor Castle is a little under 1,000 years old; it was begun around 1070 in the 11th century, so in 2026 it is about 955 years old.

Quick Scoop

  • Construction started under William the Conqueror around 1070, shortly after the Norman Conquest.
  • It took about 16 years to complete the original timber motte-and-bailey fortress, finishing in the 1080s.
  • That makes Windsor Castle roughly 950+ years old today, often described as “nearly 1,000 years old.”
  • It is also considered the oldest continuously occupied castle in the world, used by English and later British monarchs since the time of Henry I.

In forum and travel guides, people usually phrase it as: “Windsor Castle is nearly 1,000 years old,” because it dates back to the late 11th century and has been altered many times since.

Extra context and “latest” angle

  • Modern visitor guides in 2025–2026 still highlight its 11th‑century origins and emphasize its status as a working royal residence and major tourist attraction.
  • Recent articles also note green upgrades and conservation work, showing how this almost‑millennium‑old fortress keeps being adapted for 21st‑century use.

TL;DR: When you ask “how old is Windsor Castle,” the everyday answer is: it’s about 950–1,000 years old, originally built around 1070 in the 11th century. ✅

Information gathered from public forums or data available on the internet and portrayed here.