In 1516, Charles V succeeded his grandfather Ferdinand of Aragon as King of Spain.
Charles was also ruler of the Low Countries, centre of a great deal of English trade and bordering on France, therefore a convenient base for attack.
In 1519, Charles succeeded his other grandfather, Maximilian as Emperor of Germany.
For Henry VIII, Charles seemed an ideal ally against France as he was apparently so powerful and since the French were seriously concerned about Hapsburg encirclement
With relations worsening between Charles and Francis, Wolsey attempted to act as peacemaker. In 1521, he met Francis I in Calais and Charles V in Bruges.
After the failure of these negotiations, Henry agreed to an alliance with Charles against France.
Charles visited England in 1520 and 1522 and England then declared war on France (June 1522).