I really love flag cards, but, unfortunately, I've received only 3 so far! So I don't have to explain my happiness, when I found this card in my mailbox :) I received it as a thank you card, because my 1st official card to this user got lost and I sent one more after a month. That's funny that my postcards arrive in many countries that are not so well developed (and where they'd more likely get lost), but exactly the one sent to an European country disappeared somewhere.
The Union Flag, also known as the Union Jack, is the national flag of the United Kingdom of Great Britain and Northern Ireland. Historically, the flag was used throughout the former British Empire. It retains an official or semi-official status in some Commonwealth Realms, e.g. in Canada, where it is known as the Royal Union Flag. The current design dates from the Union of Great Britain and Ireland in 1801.
When King James VI of Scotland inherited the throne of England and was crowned James I of England in 1603, the crowns of the Kingdom of England (which since 1535 had included Wales) and the Kingdom of Scotland were united in a personal union through him. Despite this Union of the Crowns, each kingdom remained an independent state.
On 12 April 1606, a new flag to represent this regal union between England and Scotland was specified in a royal decree, according to which the flag of England (also representing Wales by implication), (a red cross with a white background, known as St George's Cross) and the flag of Scotland (a white saltire with a blue background, known as the Saltire or Saint Andrew's Cross) would be "joyned together according to the forme made by our heralds, and sent by Us to our Admerall to be published to our Subjects." This royal flag was at first only for use at sea on civil and military ships of both Scotland and England. In 1634, King Charles I restricted its use to the monarch's ships. Land forces continued to use their respective national banners. After the Acts of Union 1707, the flag gained a regularised status, as "the ensign armorial of the Kingdom of Great Britain", the newly created state. It was then adopted by land forces as well, although the blue field used on land-based versions more closely resembled that of the blue of the flag of Scotland.