Alun Michael's former special adviser, Delyth Evans, was sworn in as his replacement in the Welsh Assembly.
The former First Secretary formally severed his links with the Assembly on 1 May, reverting to his Westminster role and bringing to a close his unhappy association with the Assembly.
Mr Michael resigned as first secretary in February just before a Plaid Cymru-inspired vote of no confidence in his leadership.
The vote followed what Plaid regarded as the failure of the then first secretary to secure Treasury match-funding for £1.2bn worth of European grants for deprived areas of Wales.
His departure paved the way for Delyth Evans who was the second name on Labour's regional list of candidates for Mr Michael's former seat of Mid and West Wales.
Under the Assembly's election rules, no by-election is necessary for the regional seat - the next candidate is automatically appointed.
A former assistant to late Labour leader John Smith, Ms Evans knows her predecessor well.
Until his resignation, she was one of Mr Michael's special advisers in the Assembly.
She is a Welsh speaker, and recently argued in an Assembly debate on the language that no new legislation to promote the language was currently necessary.