When the Rev. Rajko Kosic prepares his weekly Sunday sermon, he works twice as hard as most ministers because he delivers one in Serbian, the ethnic language understood by almost half of his congregation, and one in English.

"The one in Serbian is usually shorter," Father Kosic said. Each sermon has a different topic to keep interest, he said.

Father Kosic, 38, has been pastor for six years at the Holy Trinity Serbian Orthodox Cathedral. The church, at 450 Maxwell Drive, with its signature shiny domes and stainless steel crosses, has been a Whitehall landmark since 1971.

On Nov. 3 through 5, the cathedral will celebrate Serbian Orthodox Heritage Weekend to commemorate the 100th anniversary of the establishment of the first Serbian Orthodox church in Pittsburgh. That church was established in January 1906 in South Side as St. George Serbian Orthodox Church.

Holy Trinity Church was formed in 1961 with the unifications of St. George and St. Sava, another South Side church, which was founded in 1935.

A six-acre parcel for the church was donated by Mrs. Louise Thoma Colteryahn, in memory of her husband, Carl. The church has more than 300 members and is one of three designated orthodox cathedrals.

"From the time Serbian people first arrived on Pittsburgh's South Side, they have worked together to preserve their heritage. With a deep and abiding commitment to their faith, they overcame strife, the Great Depression, cramped quarters and other challenges," Father Kosic said.

Boja Mamula, who will be 104 on Jan. 15, is one of several members who have lived through most of the church's Pittsburgh history.

The South Side woman is known affectionately as "Teta," the Serbian name for aunt, by all who know her, and, according to Father Kosic, "is a remarkable woman."

Mrs. Mamula came for a special photograph which will be included in a commemorative book being prepared by the pastor. Her comments and memories, long with those of other members, will be included in the book.

"We not only look back on our past with pride and respect, but we look ahead to a brighter future," said the pastor.

Events scheduled for the celebration include music and dancing at 9 p.m. Nov. 3 at the American Serbian Club on the South Side.

Religious services at Holy Trinity involve vespers at 5 p.m. Nov. 4 and worship at 10 a.m. Nov. 5.

A special anniversary banquet will be held at 12:30 p.m. Nov. 5 at the Bradley House on Brownsville Road, Baldwin Borough.

Tickets for the banquet are $40 for adults and $15 for children age 12 and under. Reservations are required and can be made by calling 412-882-3900.

Anyone interested in making a donation to help cover some of the Heritage Weekend expenses can contact the church office.