Othello shows himself to be a stellar man and general through the manner in which he is regarded in Venice and his eloquent speech as he addresses the Senate in Act. I. Othello, in his story of "the course of love" used to woo Desdemona, discusses the near death experiences, feats of broil and battle, the strange men he has encountered, escaped from, and defeated in battle ("the anthropophagai, and men whose heads do grow beneath their shoulders" ). These experiences set him apart from other Venetians, and give them a confidence in his abilities that transcends race, which would have been a factor in giving a Moor a position of power. The Turks, or moors, would have been Venetian enemies at this time.
As Brabantio accuses Othello of witchcraft in an attempt to dismiss the marriage of Othello to Desdemona, he is shown to be a fool who does not know his own child. Othello humbles himself to his audience in a use of ethos that is unparalleled in literature. He opens saying, "rude am I in speech" and proceeds to tell a tale that would woo even the most hardened woman. No man in the room even attempts to question this marriage between a Venetian noble woman and a Moor. Othello clearly commands the respect of all who know him.
Othello is a man of great character. He is a just and fair man (early in the play). He is also a great general and is very intelligent. He is a good leader and commander. His ability to lead and to chart a course for battle is second-to-none. He is also able to remain steady-tempered and in control as those attributes relate to his military skills.
Othello also impresses the gathering of the Duke and senators when Othello defends himself against Brabantio's charges that he cast a spell on his daugther, Desdemona. Othello matter-of-factly and humbly explains that Desdemona fell in love with him after he told her stories of his troubled youth, etc. His speech is eloquent and heartfelt.
Only when Iago begins planting the seeds of jealousy does Othello's character begin to unwind and a darker side of him is seen.