Who is Isa from Beneath a Marble Sky: A Novel of the Taj Mahal and what is their importance?

Isa is Jahanara's love interest in the novel, who does not enter the story until chapter six. He tells her his background on the first day they meet. He was born in Persia to a builder and designer, but when his mother died and his father became ill, his father had him apprenticed to an architect who was from Delhi.