Afonso sent an envoy to assess support for Joanna's cause and after receiving "favorable accounts respecting the partisans of the Infanta", he ordered war preparations to be made for the following spring.

[23] In March 1476, at Toro, Afonso V and John and some 8,000 men faced Castilian forces of similar size led by Isabella's husband, Ferdinand of Aragon, Cardinal Mendoza and the Duke of Alba.

[26] Despite its uncertain[27][28] outcome, the Battle of Toro represented a great political victory[29][30][31][32] for Isabella and Ferdinand and Afonso's prospects for obtaining the Castilian crown were severely damaged.

[34] Months after the Battle of Toro, in August 1476, Afonso V travelled to France hoping to obtain the assistance of King Louis XI in his fight against Castile.

[49][50] At the Cortes, John further enraged nobles by declaring that property title deeds would undergo examination to ensure their validity, as opposed to being confirmed in mass.

[53] By 1482, Fernando, Duke of Braganza, the wealthiest nobleman in Portugal, and his followers had begun conspiring for John’s deposition, allegedly receiving support from the Catholic Monarchs.

[54][57] Braganza’s execution caused even more intrigue among the upper-nobility, who rallied behind Diogo, Duke of Viseu, John’s cousin and brother to his Queen Consort, Eleanor.

[64][65] The immense profits generated by African ventures[66] enabled the king to fund exploration expeditions, reduce his reliance on the cortes for financial support,[67] and strengthen the monarchy's power over the nobility.

[72][73][74] The Portuguese explorations were his main priority in government, patronising both local and foreign men, such as João Afonso de Aveiro and Martin Behaim, to further his goals.

Portuguese explorers pushed south along the known coast of Africa with the purpose of discovering the maritime route to India and breaking into the spice trade.

[95] That meeting also proved unsuccessful, in part because not long afterwards Bartolomeu Dias returned to Portugal with news of his successful rounding of the southern tip of Africa (near the Cape of Good Hope).

[99] John II welcomed him warmly but asserted that under the Treaty of Alcáçovas previously signed with Spain, Columbus's discoveries lay within Portugal's sphere of influence.

[104][105] John sanctioned several anti-Jewish laws at the behest of parliamentary representatives, including restrictions on Jewish clothing and the emancipation of Christian converts owned by Jews.

[108][112] Many[f] children of the enslaved Castilian Jews were seized from their parents and deported to the African island of São Tomé in order to be raised there as Christians and serve as colonists.

[59] The king wanted his illegitimate son Jorge to succeed him but Queen Eleanor was intent on securing succession for her younger brother Manuel, the legal heir presumptive.

[116][117] Following bitter disputes with Eleanor and a failed petition to Rome to have Jorge legitimized, John finally recognized Manuel as his heir in his will while on his deathbed in September 1495.