Source 1: Investment in a Naval Voyage
Merchants and financiers, like Jaume Nadal of Perpignan and his partner, invested in voyages that might produce booty and slaves in the same way they did those of merchants traveling from port to port with their goods. Jaume Nadal was the former ward of his skilled financier grandfather, Arnau de Codalet. This document is a register entry from a notarial protocol from 1276-1287 devoted to the affairs of de Codalet, his family, and associates. Although re-investing funds that monasteries and noblewomen entrusted to the de Codalets was a specialty of this successful family business, the de Codalets had a diversified portfolio. Jaume Nadal, and probably the rest of his family, thought investment in arming and supplying a ship heading out to fight against Muslims, (probably in Tunis under the banner of King Pere El Gran), was shrewd financial speculation, whether they were expecting a return on their investment in booty or slaves or both. Individual ship captains, like Jaume de Brassa of Majorca, eagerly participated in naval campaigns against Muslim powers in hopes of capturing slaves just as naturally as they might have in carrying cargoes.
 See Thomas Bisson, The Medieval Crown of Aragon (Oxford: Oxford University Press, 1986) 87.
Translated from the Latin by Rebecca Lynn Winer. Perpignan, France, Archives départementales des Pyrénées orientales (ADPO), Notarial Series 3E1 Register 8, folio 39v. This translation CC BY-NC-ND 4.0.
Investment in a Naval Voyage
8 January 1282
I, Jaume de Brassa, sailor from Majorca, acknowledge and recognize to you Jaume Nadal of Perpignan and you Ramon Fanoni that you have and should have 50 sous of Barcelona concerning which [money is worth in silver etc.] which I invested in the preparations of my ship and the armament of the same ship of my own, when– let it be right away, we will go on a military campaign against the enemies of the faith and the holy cross [the Muslims of North Africa], I promise to you that I will give or pay you the eighteenth part of all the profits that I make –with God giving, in the said voyage that soon I will make against the enemies of the holy faith, an eighteenth part of the profits I promise to repay to you …immediately, when I return, when the Lord grants, from this time on –if God will have come to grant mercy– and I obligate my [goods] etc. and I swear, through which oath, I promise to you to repay the deposit and all of the interest or all the profit which I make– when God grants, in the present voyage I wish [to undertake] when etc.
The witnesses are Bernat de Murcia, Bernat Jausbert and Bernat Miró.
I [the notary] have 4 pennies [paid to record this investment transaction].