Why 1385?

It was the date when Edmund of Langley was created first Duke of York, so it seems as good a starting point as any. To set the scene, the 'pacifist' Richard II was invading Scotland with the biggest army since Bannockburn. (Richard was not afraid of fighting in a good cause - in this case he was cheesed off because the French had landed troops in Scotland, thus creating a threat to English security.)

Along the way he gave his two younger uncles dukedoms. (Thomas of Woodstock, Earl of Buckingham, became Duke of Gloucester.) Their elder brother, John of Gaunt, Duke of Lancaster, pretend King of Castile and Leon, etc., etc., was already suitably elevated, plus he had the lithesome Katherine Swynford to play with, so Richard wanted to square things up a little.

There was just one small snag. Money, or to be precise, the land that generated it in those days. (There was no stock market, and dukes couldn't part time it as architects or whatever.)

Thomas of Woodstock had married a nice heiress, but poor old Edmund of Langley's wife was Isabel of Castile, who had brought him diddly squat apart from a few jewels. (They had even had to sign her claim to Castile over to big brother John, who had married her elder sister.)

I don't want you to cry too much for Edmund, compared to the average ploughman or milkmaid we are mostly descended from he was on a nice little earner. But as medieval dukes went, he was pretty well on the bottom rung. Richard II gave him a grant from the exchequer of £1000 a year to support his dukedom, but the problem was that in those days the king (unlike modern politicians) could not just bleed everyone white with taxation. The exchequer was often empty, and Edmund could not rely on his salary cheque. The grant was supposed to be gradually replaced with land, and from time to time he and his successors got a manor or two tacked on to their rent roll. However, it remained a problem, even for Edmund's grandson, as I shall likely tell you when we get on to the third Duke.