Information about the powers and responsibilities of the British royal family?

I need information about the domestic/political/foreign powers and responsibilities of the British royal family and how their powers have changed over time. A reference to a book or reliable website would be appreciated and proffered.Information about the powers and responsibilities of the British royal family?Start here and go onto the other sections:

http://www.royal.gov.uk/MonarchUK/Howthe鈥?/a>

"Monarchy is the oldest form of government in the United Kingdom.

In a monarchy, a king or queen is Head of State. The British monarchy is known as a constitutional monarchy. This means that, while The Sovereign is Head of State, the ability to make and pass legislation resides with an elected Parliament.

Although the British Sovereign no longer has a political or executive role, he or she continues to play an important part in the life of the nation.

As Head of State, The Monarch undertakes constitutional and representational duties which have developed over one thousand years of history. In addition to these State duties, The Monarch has a less formal role as 'Head of Nation'. The Sovereign acts as a focus for national identity, unity and pride; gives a sense of stability and continuity; officially recognises success and excellence; and supports the ideal of voluntary service.

In all these roles The Sovereign is supported by members of their immediate family. "

http://www.royal.gov.uk/MonarchUK/Howthe鈥?/a>

talks about the history and background of the monarchy.

http://www.royal.gov.uk/MonarchUK/Howthe鈥?/a> talks about the Constitutional Monarchy of the UK.

http://www.royal.gov.uk/MonarchUK/Howthe鈥?/a>

http://www.royal.gov.uk/MonarchUK/Howthe鈥?/a>

http://www.royal.gov.uk/MonarchUK/Howthe鈥?/a>

http://www.royal.gov.uk/MonarchUK/Howthe鈥?/a>

are some other sections.