Please bear with any confusing explanations – this is my first question on here.
I’ve started building a fantasy world with the rough geography and technological advancement of late 14th –15th century Europe. I've attempted to research resource production in this period, but I've been unable to find an answer I could make sense of and apply to my specific case.
My story is focused around an island off the Southern coast of the continent with a climate similar to that of Italy or Southern France – think hot summers and warmer winters, but with plenty of rain to keep crops growing. They’ve got two central forested mountains from which they’ve been mining gold for three hundred odd years, but most of the island is rolling plains with woodland here and there. In my head it’s roughly half the size of Northern Ireland.
(At least, that’s what I’m hoping. If the logistics don’t work I’m more than willing to change all of this.)
For my plot to work, the family that owns this island need to be rich – one of the richest in the country in fact, as the king wants to marry their daughter mostly for their wealth.
The gold mine helps with that, but it’s not consistently fruitful, and past years of scarcity have led the family to diversify into other areas. They also grow vines and make some of the best wine to be found anywhere, and breed a small number of very fine horses that they sell almost exclusively to the royal stables. These are enterprises for which they’re famed, but due to their high quality-low yield preference, I don’t think it will make them enough to keep them on the “Forbes Richest List”!
For their main area of income, I’d like the island to be one of the “breadbasket” areas of the country, who supply grains and vegetables and fruits primarily to the capital (on the coast almost directly north of the island, pop. 1million**) and other nearby towns and cities. They’re not the sole provider to those areas, but they do contribute a significant enough percentage that the capital would face food shortages if the island was to stop supplying food for whatever reason – say 5% of general food, but more like 15-20% of the nobility’s food as they favour the “exotic” fruits the island can provide.
Is it feasible for an island of my envisioned size (c. 7,000km2) and climate to supply that amount of food?
Would I be better off bumping up their gold mining, horse breeding and wine production and having them grow only enough food to supply their own population (c. 50,000 people)?
Please feel free to ask me to clarify anything I’ve explained poorly.
** EDIT: Thank you to all who've pointed out that this population is too high. I've phrased this poorly and meant to say that the 1 million population is that of the capital and towns and cities along that southern coast combined. This is still too high, so I'm going to reduce the overall number to 700,000 to be more in line with recommendations below.