import unicodedata


def strip_str (string):
    """Removes diacritical markings from a string and makes lowercase.
    
    :param str string: a string of text
    :return: a string of text without diacritical markings
    :rtype: str
    """
    bare_str = ''
    for ch in string:
        bare_ch = unicodedata.normalize('NFD', ch)[0]
        bare_str += bare_ch
    bare_str = bare_str.lower()
    return bare_str