wrought

Wrought is an old past tense and past participle not of wreak (for which the past tense is wreaked) but of work: it is the equivalent of modern worked. Wrought survives mainly as an adjective in a few, rather specialized contexts such as wrought iron; it is seen also in the set phrase What hath God wrought (used by Samuel Morse in the first successful test of the telegraph). Wrought havoc is not correct; it should be wreaked havoc.