He married a woman who was a new Muslim without the permission of her parents, then they gave their approval after that
Question

                I got married almost 3 years ago but I have always questioned myself if my marriage is valid or not. I have always considered myself a religious man who follows the 5 pillars of Islam and does a lot of dawah. Previously I went to work and offered my assistance at a Masjid and Madrassa in another country for approximately 2 years. After the first year I was interested in getting married to a 22 year old new Muslimah convert from the country I was working in who also used to volunteer sometimes in the same madrassa I was working in. Because she was a new convert and her family was not Muslim, she did not have a Wali. She told her parents that she wanted to get married to me and they agreed at first but they wanted to talk to the Imam of the Masjid I was working in since he was the only Islamic authoritative figure in that country. They wanted to hear from the Imam if Islam permits their daughter to get married to me so soon. So the parents and her went to the Masjid together to meet with the Imam and the Imam told them that she should not get married to me and that she should delay her marriage until he finds someone from the same nation and just to be my friend but not more. The parents took the Imam’s advice because they already thought she shouldn’t get married since it was strange to get married so soon in their culture. The Imam just supported them by telling them what they wanted to hear (that she shouldn’t get married). I and other brothers were very disappointed at this because the Imam was preventing us to get married and we thought this was not fair or right. I have read some articles from your website saying a new Muslim convert does not have to inform her non- Muslim parents if she is getting married to a Muslim and an Imam can act as her Wali. So I thought it would be okay to not tell her parents and get married to her by having my local Imam in my country act as her Wali since the imam in her country told her and her parents not to marry me. We took the liberty of flying to my home country and marrying there through my local imam in front of 3 Muslim witnesses. However, I’m not sure if what I did was permissible or not and if my marriage is valid because she traveled with me to my home country without a Mahram. Her parents found out later that we got married and they have no problem with us being married now and we have been living together now for almost 3 years. However, I still need some clarification in this matter and need to know if I did the right thing. Could you please help and advise me?.
Praise be to Allah.
      First of all, we share your astonishment at the answer of 
      this imam whose was not wise and was not appropriate to the case that was 
      presented to him. Yes, a person could advise one who wants to get married 
      in ordinary circumstances to marry someone from the same country or region 
      as himself, so as to avoid differences in customs, traditions and so on, 
      which can cause a lot of family problems, let alone the possible 
      consequences of staying away from one’s country, such as severing of 
      family ties and the like. 

    But with regard to your problem, the matter is different in 
    all aspects. Hence the advice of this imam was not appropriate. Moreover, 
    giving advice is one thing and explaining the Islamic ruling to one who is 
    asking about it is something else. If the imam was being asked for Islamic 
    advice, he should have explained the ruling of Islam on the matter being 
    referred to him, then after that he could give his advice in the light of 
    what he thinks is in the best interests of the questioner. 

    Secondly: 

    If you did your marriage contract with this Muslim girl, with 
    the proposal and acceptance as prescribed in sharee‘ah, and all the pillars 
    or essential requirements of marriage were fulfilled, and the marriage 
    contract was done by the imam of the neighbourhood in which you live or by 
    the director of the Islamic Centre in your locality, then your marriage to 
    this girl is valid. But in fact you did not need to travel with her without 
    a mahram; this is something that was not permissible for you. And you should 
    not have married her far away from her family, because they were not opposed 
    to your marrying her and they were not opposed to her in her choice of 
    religion. You could have brought her family to where you live or brought 
    some of them, and the marriage could have been done in the proper Islamic 
    fashion and in an appropriate social environment, so that her family could 
    have attended and it would not have appeared to exclude them or go against 
    their wishes. 

    But whatever the case, so long as the matter is done and 
    there have not been any problems with your wife’s family, then the marriage 
    is valid even though there was the issue of your travelling with her without 
    a mahram, which against the teachings of Islam. May Allah forgive you and 
    her. 

    See also the answer to question no.
    2127 and
    389 

    And Allah knows best.