I keep running into people who are somewhat puzzled and perplexed as to the difference between England, Britain, Great Britain, and the United Kingdom (UK). There’s no need to be ashamed if you are befuddled, bemused, confounded, or confused yourself, because even people who were born and bred on the sceptered isle tend to be a little fluffy around the edges with regard to this topic. The easiest way to wrap your brain around all this is by means of a diagram as shown below.

England vs. Britain vs. Great Britain vs. The United Kingdom (Click image to see a larger version)

Let’s start with the fact that England and Scotland are kingdoms, while Wales is a principality. Britain refers to the combination of England and Wales. This name was made popular by the Romans, who used the term Britannia when they invaded the British Islands (Julius Caesar first attempted to invade Britain in 55 BC and returned to complete the job in 54 BC. However, the real Roman conquest of Britain began almost 100 years later in AD 43 under the Emperor Claudius. Following a full-blown occupation, the Roman colony of Britannia was established.)

By comparison, Great Britain refers to the combination of Britain (England and Wales) and Scotland, while the United Kingdom (UK) refers to the combination of Great Britain and Northern Ireland (Southern Ireland or Éire, also known as the Republic of Ireland or Poblacht na hÉireann, is a sovereign state).

Also, while we’re on this topic, there’s a difference between the terms “British Islands” and “British Isles.” The British Islands consist of the United Kingdom, the Channel Islands (the principals of which are Guernsey and Jersey), and the Isle of Man. (In case you were wondering, the Isle of Wight, which is located off the south coast of England, is considered to be a county, i.e., a part of England.) Meanwhile, the British Isles is an archipelago consisting of the two large islands of Great Britain and Ireland, along with over 6,000 smaller surrounding islands. All of this is best illustrated using a Euler diagram, as shown below.

British Islands vs. British Isles (Click image to see a larger version)

In turn, this leads us to the topic of the Union Jack or Union Flag, which — strange as it may seem considering the fact that it’s so well known — is only the unofficial de facto national flag of the United Kingdom.

The Union Jack combines aspects of three older national flags: the red cross of St George for the Kingdom of England, the white saltire of St Andrew for Scotland, and the red saltire of St Patrick to represent Ireland (although the southern part of Ireland is no longer part of the United Kingdom).

Three flags form the Union Jack (Click image to see a larger version)

I remember as a kid watching a black-and-white cowboy program on TV. As part of this, our hero the sheriff notices that an English expatriate has the Union Jack flying upside down outside his log cabin. Understanding this to be a sign of distress, the sheriff subsequently captures the bad guys who are holding the English guy hostage.

The reason this works is that the Union Jack has rotational symmetry (you can rotate it 180 degrees and it will still be the right way up) but not reflectional symmetry (you can’t invert it around its horizontal axis). This is due to the slight pinwheeling of the St Patrick’s and St Andrew’s crosses (technically a “counterchange of saltires,” but I’m sure you already knew that).

Get it right (Click image to see a larger version)

The easy way to determine whether the flag is oriented correctly is that on the hoist side of the flag — the side next to the flagpole — the thick white band should appear above the thin red band on both diagonals.

The reason I mention all of this here is that my son, Joseph, informed me that he’d recently seen a green flag with a small Union Jack in the corner and he wanted to know its provenance. Sad to relate, I was forced to admit that I didn’t have a clue — how about you?