I am currently trying to unravel the arrangements for the Despenser lands in the late 14th Century. It is quite complex.
When Edward, Lord Despenser died in November 1375, the wardship of his lands was given to his widow, Elisabeth. This was an unusual mark of favour and may reflect the fact that Sir Edward had been one of England's premier knights and was very well-regarded. Elisabeth also had a third of the lands in dower plus her inherited Burghersh lands which belonged to her in her own right. This made her a very wealthy and powerful woman, and all indications are that she did a very good job of protecting her son's lands rather than asset-stripping them as 'guardians' often did.
Of course, the grant was not absolute. She 'farmed' the wardship (which ultimately belonged to the King) and had to pay a fat annual fee for the privilege. This was quite normal practice. Some of that fee was certainly paid to the Duke of York, whose daughter was married to her son Thomas around about 1379. (They were both very small children.) This began a process where various members of the York family lived off the part of the Despenser revenues right up until 1415/16. But that's another story.
In December 1390, when Thomas was still only 17, he was associated with his mother in his own wardship. This was very unusual and shows a degree of favour from Richard II. However, it applied to only part of the inheritance. The two-thirds of Glamorgan not forming Elisabeth's dower were covered as was a selection of the English lands but by no means all of them. For this Thomas and Elisabeth had to pay £700 a year to the King plus smaller amounts to various people who had been given incomes based on the issues of the wardship. The implication is that the lands must have been worth more - perhaps much more. When it is borne in mind that the Duke of York's landed income was only £900, it shows how valuable the Despenser lands must have been.
How this worked in practice is hard to discern, but it looks like Elisabeth retained charge of much of the English inheritance. The purpose of this split eludes me.
In 1394 when Thomas was twenty, he was allowed full livery of all his lands some months before his birthday. This concession may have related to his decision to go with the King to Ireland, and the downside to it is we do not get a Proof of Age as he was never required to obtain one. This deprives us of a great deal of knowledge. Again, some people were given protection until he truly came of age, but he would have had the bulk of his inheritance and his mother's duty was at an end.