Nuncio to Bulgaria

On 8 July 2000, Mennini was appointed Titular Archbishop of Ferentium by Pope John Paul II and Nuncio to Bulgaria. Mennini received episcopal consecration on 12 September from Cardinal Angelo Sodano, assisted by Cardinals Camillo Ruini and Jean-Louis Tauran as co-consecrators.

Upon arrival in Bulgaria, Mennini began preparing Pope John Paul II’s 2002 pastoral visit to Bulgaria amid great controversy. However, the visit was hailed as a success, largely because the new nuncio established excellent working relations with Orthodox leaders who had originally opposed it.^[4]

Nuncio to Russia and Uzbekistan

On 6 November 2002, Mennini was appointed Nuncio to Russia^[7] and from 26 July 2008 was also Nuncio to Uzbekistan.^[8] He is credited with notably improving the Holy See’s relations with the former Soviet republics and with the Russian Orthodox Church.

As recently as 2001 Rome had been criticised by the Russian Orthodox for setting up Latin Catholic dioceses in Russia without adequate consultation. However, through the nuncio’s fence-mending efforts, the atmosphere gradually began to improve and in December 2009 President Dmitry Medvedev approved the establishment of full diplomatic relations with the Holy See.^[9] On 13 February 2011 Dmitry Medvedev awarded Mennini the Order of Friendship for his contribution to the development of Russian-Vatican relations.^[10]

Nuncio to Great Britain

Mennini was named Nuncio to Great Britain on 18 December 2010^[11] following the early retirement of Archbishop Faustino Sainz Muñoz on 2 December 2010.^[12] He presented his credentials to Queen Elizabeth II on 2 March 2011.^[13]

As a Nuncio, one of the most important duties which Mennini faced was to facilitate the vetting process for the appointment of a substantial number of new bishops for dioceses in England, Wales and Scotland, referring back the results of confidential consultations to the Holy See.

On 25 February 2013, Pope Benedict XVI accepted the resignation of Cardinal Keith O'Brien, Archbishop of St Andrews and Edinburgh and Britain's then most senior cleric. Two days later, the Pope likewise accepted that of Patrick Altham Kelly, Archbishop of Liverpool. Mennini played a role in the appointment of their successors.

A writer in the English Catholic publication The Tablet speculated that Mennini's appointment was recognition that delicate diplomatic work was required for the establishment in Britain of the personal ordinariate for former Anglicans.^[4]

Secretariat of State

On 20 January 2017 it was announced that Mennini was to be transferred to the Roman Curia to serve in the Secretariat of State. His tenure in Britain ended on 6 February. In his new post he is responsible for monitoring relations between the Holy See and Italy.^[14]