Except for Vatican-purchased and approved annulments. Even a marriage that has produced legitimate children and been sanctioned in a RC church in a ceremony conducted by a RC priest can be "annulled" for spurious reasons.
Even a marriage that has produced legitimate children and been sanctioned in a RC church in a ceremony conducted by a RC priest can be "annulled" for spurious reasons.
Marriage exists if a freely undertaken informed consent to marry exists for both sides. The ceremony, Catholic or otherwise, is merely an ourtward expression of such consent. If, for example, a marriage involved a prior bond (such as a previous marriage or holy orders), or was not open to procreation, or was not intended for life, or fidelity was not intended, then such marriage is likely invalid, no matter what ceremony.
Which, by the way, explains why the annulments are so common: because the modern culture of marriage produces marriages that are largely invalid.
For completeness, in addition to consent, there needs to be another factor for an annulment: the marriage no matter how implausibly conceived must be challenged by one or both putative spouses. An unchallenged marriage is presumed valid.