---
title: Greenwich Royal Observatory
author: Tilman2007
source: https://www.worldhistory.org/image/22335/greenwich-royal-observatory/
format: machine-readable-alternate
license: Creative Commons Attribution-ShareAlike (https://creativecommons.org/licenses/by-sa/4.0)
updated: 2026-11-09
---

# Greenwich Royal Observatory

_Authored by Tilman2007_

## Image File

[![Greenwich Royal Observatory](https://www.worldhistory.org/uploads/images/22335.jpeg)](https://www.worldhistory.org/uploads/images/22335.jpeg)

## Image Caption

Greenwich Royal Observatory, photograph by Tilman2007, 24 July 2006.

Shown here is the Greenwich Royal Observatory in London, home of Greenwich Mean Time, which became the legal [timekeeping](https://www.worldhistory.org/Timekeeping/) standard for all British [railways](https://www.worldhistory.org/disambiguation/Railways/) in 1847 and later, during the 1884 Meridian Conference, it was chosen as the base time zone for a universal system shared across 25 countries. An interesting feature of the building is the red time ball on top of the roof, which is used to signal the correct time. Each day, it rises on its mast and then falls at exactly 1 p.m.

## Cite This Work

### APA
Tilman2007. (2026, November 09). Greenwich Royal Observatory. *World History Encyclopedia*. <https://www.worldhistory.org/image/22335/greenwich-royal-observatory/>
### Chicago
Tilman2007. "Greenwich Royal Observatory." *World History Encyclopedia*, November 09, 2026. <https://www.worldhistory.org/image/22335/greenwich-royal-observatory/>.
### MLA
Tilman2007. "Greenwich Royal Observatory." *World History Encyclopedia*, 09 Nov 2026, <https://www.worldhistory.org/image/22335/greenwich-royal-observatory/>.

## License & Copyright

[![copyright source](/images/partners/wikipedia-small.png)](https://commons.wikimedia.org/w/index.php?curid=35517862)Based on [Wikipedia](http://www.wikipedia.org/ "Wikipedia") content that has been reviewed, edited, and republished. [Original image](https://commons.wikimedia.org/w/index.php?curid=35517862) by [**Tilman2007**](https://commons.wikimedia.org/w/index.php?curid=35517862). Submitted by [Alex Ram](https://www.worldhistory.org/user/alexram/ "User Page: Alex Ram"), published on 09 November 2026. The copyright holder has published this content under the following license: [Creative Commons Attribution-ShareAlike](https://creativecommons.org/licenses/by-sa/4.0deed.en). This license lets others remix, tweak, and build upon a work even for commercial reasons, as long as they credit the author and license their new creations under the identical terms. When republishing on the web a hyperlink back to the original content source URL must be included. Please note that content linked from this page may have different licensing terms.