Tunnage and Poundage had traditionally been voted to the monarch at the start of Parliaments only since 1414; the revocation of the traditional grant to Charles I in 1625 was meant to force the monarch to ask for it each year, partly as a way to curb spending and partly to show disapproval of Charles' marriage to a Roman Catholic.

Before Charles took the throne, of course, he had been intended to marry the Infanta of Spain (that is, Maria Anna, the daughter of King Philip III) but the match broke down over the Spanish insistence that England tolerate Catholicism and repeal the anti-Catholic Penal Laws. The English parliament had been actively hostile towards the "Spanish Match", and Charles and his father King James saw this as an attack on royal prerogative.

After the failure of the "Spanish match," Parliament pressed for a war on Spain. James had fallen ill and died in 1625, and during his illness Charles and the Duke of Buckingham assumed de facto control of the kingdom. Bowing to public opposition to an alliance with Spain, Charles instead married the French princess Henrietta Maria (delaying the opening of Parliament to avoid open opposition), which inflamed the parliamentarians even more. They feared that Charles would promise toleration to Catholics, and though he denied it in public, he pledged to do so in a secret treaty with Louis XIII and furthermore put an English naval detachment under French orders to suppress the Protestant Hugenots.

Parliament was afraid of the costs of a land war in Europe, and proposed instead that an English fleet be sent to attack colonies in Spain -- the idea being that treasure from the expedition would pay for itself. In the event, the grant of £140,000 and the revocation of tunnage and poundage was intended to deny Charles the funds for a land war, as well as to humble him.

Just as a little background, beyond the specific tensions between Charles and Parliament already apparent when he became king discussed above, fiscal responsibility had already become a major issue between the Stuarts and Parliament.

Some of this goes back to Elizabeth. Although by the time of Charles I, Elizabeth had acquired something of a retrospective romantic gloss and most would not have consciously attributed any of these issues to her by then. She was a single woman with no children so right off the bat her court was much less expensive than the Stuarts. She didn't have a consort or heirs that needed to be supported. But Elizabeth was also just very tight with a penny. It was a characteristic that drove her ministers insane. She was very wary of any protracted wars because of their cost. Most of her ministers went into debt working for her unless they had great wealth (Francis Walsingham's letters demonstrate a lot of the frustrations this caused.) All of the great art and architecture associated with the Elizabethan age was encouraged by Elizabeth, who enjoyed theater and poetry and art, but she wasn't a direct patron of any of it. Elizabeth tried very hard to live within her means, which is actually a rather rare trait in a monarch.

Her cheapness may have been in her nature but there was a very specific, strategic reason she did this. She didn't want to be beholden to Parliament. If she didn't need money from them then she didn't have to call one or listen to a word they said. And there were a lot of abuses that Parliament wanted addressed (for instance Elizabeth granting "monopolies" on certain goods to her favorites, in lieu of giving them gifts or money, which, again, she hated to be parted with.) At the end of her reign, she was spending beyond her means due to the Spanish war. And she did have to call a Parliament. And they did seek to address this. But she was an old woman, had been Queen for over forty years, and she was still more than capable of evading a confrontation (one of her greatest skills). So, for the most part, all of the grievances that were building up under Elizabeth went unaddressed.

See, this goes to the core of the issue, Parliament functioned because it held the purse strings. For most of her reign, it was difficult to get anything from Elizabeth that she didn't want to give. Because she wasn't desperate for money. The problem arose when James I was equally unwilling to give great concessions to Parliament but also desperately needed cash.

When James I took the throne and he didn't want to be beholden to Parliament either (he was much more vocal, eloquent and arguably impolitic on this issue but fundamentally his views weren't different from his predecessors.) However, James I was in much more desperate need for cash. Partly, this is not his fault. He had a wife and children who needed to be supported with their own rooms and allowances. But a lot of it was because he could be a reckless spender and he was very generous with his courtiers (aside from granting monopolies and with a few exceptions for special favorites Elizabeth's courtiers were generous to her not the other way around). He accumulated a great deal of debt in relatively short time.

Parliament and James could never get on the same page when it came to finances. His needs were fairly immense and what he was willing to give up in exchange was never quite enough (although he absolutely was willing to compromise to a degree.) There were several long, protracted negotiations between the King's ministers and Parliament for grants of money in exchange for concessions but they ended with James dismissing Parliament in frustration.

This lead to James and his men exploiting the existing revenue streams for the king to the full and finding a lot of new and creative ways to make money without Parliament. James went between the years of 1614 and 1621 without calling a Parliament meanwhile raising money through alternative means.

By the time of Charles, Parliament wanted both to prevent the king from spending lavishly like his father and prevent the king from having too many alternative sources of revenue rendering Parliament unnecessary. Needing annual grants of Tunnage and Poundage went toward the goal of keeping Parliament involved in the purse.

There were also the specific tensions centered on Charles, himself, already described. This is just meant as additional background.