Perhaps the Renaissance introduced an era of portraiture due to the increase of self identity and introspection instead of the previous era of purposeful selflessness under the influence of religious meekness.
Another reason is that, rather than Scholasticism and wrote memorization, the individuals of the Renaissance begin to move towards independent thinking and in turn creation of their own work (and their own face).
Perhaps another reason is that there is a lot of patronage of the arts at this time and, when wealthy people pay for paintings, they want themselves inserted within the piece. This likely led to the increase of portraiture.
Another reason is that, rather than Scholasticism and wrote memorization, the individuals of the Renaissance begin to move towards independent thinking and in turn creation of their own work (and their own face).
Perhaps another reason is that there is a lot of patronage of the arts at this time and, when wealthy people pay for paintings, they want themselves inserted within the piece. This likely led to the increase of portraiture.