The Anglo-Scottish War was a conflict fought in the Scottish Lowlands between England under the rule of Henry IX, and the Scottish under the rule of James VI (though due to his age his regent was James Douglas.
The Anglo-Scottish War began after Mary I, convinced Henry IX of England to invade Scotland so she could be placed back on the throne. After she had helped look after his daughter (the future Elizabeth I of England) Henry was obliged to help, and so in January, 1575 he began to culminate an army and marched them to the English-Scottish border, while he did this a group of 12 warships and 2 galleons set of from London to Edinburgh to blockade the city. By July 1, the ships had made it to Edinburgh, only meeting a resistance of 2 warships, they then set up a blockade of the city and put it under heavy fire. Soon after this the men just south of the Scottish border began to enter Scotland, meeting easy successes along the way.
Though at first the English met with little resistance the Scottish soon fought back, ferociously defending their nation. This is why the war dragged on for 7 years, as the English couldn't push past the Duns-Ayr line, while the Scottish found it equally difficult to push through the same line. There were heavy losses in battles that culminated to nothing.
In the end the peace treaty had to be signed by both sides as they grew weary of the conflict, though the treaty was in England's favour the Scottish still signed it, as they had began to run out of food for their people due to the siege of Edinburgh and also the loss of a large amount of the Scottish lowlands. The main impact the war had was that Scotland's monarchy once again was under a Catholic queen, though she was more a puppet of Henry IX of England.
There was one, main reason as to why the Anglo-Scottish War began. This was because Mary I of Scotland had been forced to abdicate from the Scottish throne, and her 1 year old son had been placed as King of Scotland as James VI. Mary had then fled to England seeking refuge from Henry IX, who granted her it. She helped bring up his daughter, Elizabeth, and the two grew a strong bond, (some say they secretly wed, but they denied this.) Mary then used this new friendship to request if Henry would help her take the Scottish throne again. He consented to this, wishing to help his second cousin.
Siege of Edinburgh
On July 1, 1575 a group of 12 warships and 2 galleons had gotten to Edinburgh from London. They soon encircled the port of Edinburgh and blockaded it. They only met minor resistance from 2 Scottish warships which were dispatched of relatively quickly, a blockade was then made of the Port of Edinburgh and a siege took place that lasted for the entire campaign (though there were occasional weeks breaks for more supplies.) This siege of Edinburgh resulted in up to 2000 scottish civilian deaths, but only around 350 scottish army casualties, these mainly occurred whenever the ships would try to invade Edinburgh and were forced to retreat due to casualties.
Treaty of Glasgow
The Treaty of Glasgow resulted in a payment of around £100 to Scotland as repartitions for the war, while Scotland was forced to give up the land south of the 'Duns-Ayr' line, a large portion of their lowlands. The Scottish Parliament was also forced to place Mary I of Scotland back on the throne, and so James VI was forced to be taken of the throne again. Though Mary was more a puppet queen to Henry IX of England.