Zimbabwean President Robert Mugabe flew into Rome on Monday to attend Pope Francis's inauguration, sidestepping a travel ban that applies to the EU but not to the sovereign Vatican City state.
Mugabe arrived amid controversy in Zimbabwe where police on Sunday arrested four of Prime Minister Morgan Tsvangirai's aides and a prominent human rights lawyer following a referendum that would curtail Mugabe's powers.
A practising Catholic, the 89-year-old Mugabe visited the Vatican previously in 2011 for the beatification of late pope John Paul II.
In 2005, he attended John Paul II's funeral on a visit that drew controversy after Britain's Prince Charles shook hands with him.
Pope Francis's inauguration mass in St Peter's Square will take place on Tuesday, with hundreds of thousands of faithful and world leaders expected.
Mugabe has been widely condemned for human rights abuses in Zimbabwe.
Preliminary results indicate the referendum has been approved, paving the way for fresh elections to decide whether Mugabe will stay on.
The new constitution would introduce presidential term limits and beef up parliament's powers but could allow Mugabe to stay on for another decade if he wins elections.
Mugabe has ruled uninterrupted since independence from Britain in 1980, despite a series of disputed and violent polls and a severe economic crash propelled by hyper-inflation.