BOSTON — Boston’s main Catholic church is reopening for Holy Week following extensive renovations.

Cardinal Sean O’Malley will preside over the first mass at the newly renovated Cathedral of the Holy Cross on Sunday, which is known as Palm Sunday. He’ll also give his annual blessing to Boston Marathon runners, staff and volunteers ahead of Monday’s race.

The South End church is considered the Roman Catholic Archdiocese of Boston’s “mother church.” Its main worship space closed for renovations in May 2017, but two smaller chapels continued hosting services.

The church’s stained-glass windows were cleaned, oak pews were restored and a new stone floor and new wiring, sprinkler and sound systems were installed during the nearly $26 million project.

The work was funded through donations. The cathedral was dedicated in 1875.