The couple shocked fans when they announced that they'd wed on 9 May (05) in a sunset ceremony on St John in the Virgin Islands with just 35 close family and friends in attendance.
It was the first marriage for both - but following constant rumours of marital problems, Zellweger filed papers seeking an annulment at Los Angeles Superior Court on Wednesday (14SEP05).
Under American law, an annulment decrees that a marriage was invalid from the outset - and by seeking an annulment on the grounds of fraud, Zellweger must prove the country singer misrepresented facts vital to their marriage.
If either Zellweger of Chesney was under the influence of drink or drugs at the time of their marriage, it is also grounds for an annulment.
The papers also demanded the Californian court rule out the possibility of financial support for Chesney in the future.