In the 1480s, Brittany was ruled by Duke Francois II, who was under a lot of pressure from the King of France, Charles VIII, who wanted ownership of this area.
Henry VII had endeavoured to remain neutral in this situation. However, when Francois died in 1488, he left behind a twelve-year-old daughter, Anne, as his heir and the situation became more complicated. Anne agreed to pay Henry VII for a small army to act in her defence.
Maximillian, the Holy Roman Emperor, wanted to pursue a marriage with Anne in order to control Brittany himself and Henry VII, wishing to support both Anne and Maximillian, was in agreement with this plan.
Despite this, in 1490 Anne opted for marrying Charles, the King of France; placing Henry VII in a difficult position. Maximillian lost interest in the whole situation and Henry's troops were effectively marooned in France, now surplus to requirement.
To make matters worse, Perkin Warbeck resided at the French court seeking support for his cause as claimant to the English throne and thus, in 1492, Henry VII decided to invade France. With France much more concerned with invading Italy at this point, they readily agree a peace treaty with England - The Treaty of Estaples - with key conditions being that France withdraw support for Warbeck and pay Henry financial compensation for having to return his troops to England.
Not a triumphant, heroic adventure as the future Henry VIII would hope for, but a financially fortuitous and relatively peaceful conclusion for Henry VII.