You must seek entry into the United Kingdom so that your marriage can take place in the United Kingdom. And, since bridal visas are valid for 6 months, you will need to convince the Home Office that you intend to get married within 6 months of your arrival in the UK. The Home Office will usually expect to see some evidence of wedding planning and/or organizing your wedding day.
Previous relationship permanently severed
To qualify for a fiancée visa to the UK, neither you nor your fiancée must be married or in a civil partnership with another person as of the date of your fiancée visa application. You must both be free to marry.
If you were previously married or in a civil partnership, you will need to prove to the Home Office that you are divorced, your civil partnership has been dissolved, or you are widowed.
You will need to provide documentary evidence that meets the requirements of the immigration rules. For example, a divorce in the UK must be confirmed by an absolute civil court order. A divorce outside the UK must be confirmed by the reasonable equivalent of an absolute decree certificate valid under the law in the country concerned.
If you or your fiancé were previously married and that marriage has not been legally dissolved, you may still qualify for an unmarried partner visa . You will need to provide proof that the new relationship is genuine and ongoing, and that the previous relationship is permanently severed.