This is a video from http://pages.towson.edu/duncan/helhome.html, a site entitled 'The history of the English Language.' it includes links to different videos on the subject of the development of the English Language. I haven't had a chance to look at this video myself unfortunately as the computer wasn't being very cooperative, but I think that it is an introduction to the history of the English language as a topic. I thought that it was better to have a video than none at all.

Late Modern English

With the Industrial Revolution (from around 1750 - 1850) and the creation of new technology, new words were soon needed. This was a time when discoveries and investigations into different fields; science and technology. When naming the findings, scientists and engineers went back to the classical languages of Latin and Greek and created new words from ancient roots; words such as vaccine and oxygen are examples of this.
  Also at this time, the British Empire covered many parts of the globe, and during this time, global trade became more extensive, meaning that English adapted slightly and adopted the words of some other languages. Examples of this include sauna, from Finnish, Pyjamas and Shampoo from Hindi.
 In the early part of the 20th Century, a new kind of influence effected the English language. This being the influence of the Military. During the First and Second World Wars, the slang used by the soldiers have made its way into the English Language. Words such as 'Nose Dive', 'Roadblock' and Camoflague' were not used before this time.
Website references:
http://www.origin-site.com/late-modern-english.html
http://www.englishclub.com/english-language-history.htm

The Great Vowel Shift: modern English

There came a period from about 1500 to 1800 when the English language changed quite dramatically in quite a short space of time. Vowels became shorter creating a distinct change in the pronunciation of many words. Because from the end of the 16th century, the British had contact with many people throughout the world, meant that new pronunciations and phrases began to be used. The invention of printing meant that spelling and grammar became more fixed as manuscripts began to be made available to the masses. In 1604, the first English dictionary was published. It was compiled by Dr. Samuel Johnston. All the printing houses were in London, meaning that this became the standard dialect of the masses.
Sources: http://www.englishclub.com/english-language-history.htm

Middle English

In 1066 AD, the King of England, Edward the Confessor, died and William Duke of Normandy decided that this was his chance to take the throne. He invaded England and crowned himself King in the battle of Hastings. However, William only spoke French and as a result of this, although the lower classes continued to speak English, the upper classes started to speak French.

This did not last very long however and in 1204 AD, the then King of England, King John lost Normandy to the French and after this English was reintroduced into the upper classes. To reinforce this use of the language, foreigners started to come to England which made the upper classes somewhat protective of their language which led to the reintroduction of the English language to the upper classes. Although they learnt and spoke English, many still used French words when speaking.

The Hundred Years war deepened the French-English divide and made French an even less desirable language for the English to speak. This was a significant period in the evolution of the English language. English was being more widely spoken, but it was being spoken by people who had previously spoken French. This meant that many of the words changed and evolved, adapted from the French.

Grammar rules and spelling can be found at: http://homes.chass.utoronto.ca/~cpercy/courses/MESpelling.htm Here you can see the French influences in some of the spelling changes.

This Middle English, as it became known, is the language that the poet Chaucer wrote his famous Canterbury Tales in, although it still very different from the language we speak today.
Sources: http://www.englishclub.com/english-language-history.htm 

This is a Yogh, an old English charater that came to represent the letter Z but probably originally represented a gutteral G, similar to GH today.
Picture and Information source: http://www.takeourword.com/



The Old English 'Thorn' This letter was used in the place of a soft 'th' as in thistle. A different character was used in the place of more prominent 'th' such as in this and that.

Picture source: http://www.takeourword.com/



An Old English Aesc, still used in Danish and Nowegian today.
Picture from: http://www.people.w3.org/





 

The development of Old English

So this brings us to the first form of English, Aglo-Saxon English, also known as 'Old English.' This form of English was used from around 450 AD - 1070 AD. There were a few different dialects around the country; Kentish, West Saxon, Mercian and Northumbrian. These dialects weren't extremely different and probably form the basis for the different accents heard today.
The writing system they used was called the insular hand and had some different characters not recognised in today's English. These include the 'aesc', the 'thorn', the 'yodh', and the 'wynn'.
Although English is not directly influenced by the Roman's and is not a romance language, it does have some Latin influences as the Danish dialect it originated from certainly did. The tribes must have been pretty successful in their invasion, as there is nearly no Celtic influence in the English language, although old Scandinavian certainly contributed.
For the rules and grammer of Old English, go to http://www.ielanguages.com/enghist.html.