Drain artichoke hearts, reserving marinade. Set artichokes aside. Place marinade and butter in a lg. skillet. Cook over Low heat for 10 minutes. Dredge chicken in flour. Brown chicken in butter mixture over Medium-High heat. Transfer chicken to 13x9 inch baking dish, reserving butter mixture in skillet. Saute onion and next 5 ingredients in reserved butter mixture in lg. skillet until vegetables are tender. Stir in reserved artichokes, tomatoes, salt and pepper to taste. Pour tomato mixture over chicken. Cover and bake at 180ºC . for 50 minutes. Remove cover and pour Madeira over chicken. Cover and bake in aditional 10 minutes. Cook linguine according to pkg. directions. Drain well. Serve cacciatore over linguine.