Former Towson resident Bob Knowles promises "shock and awe" June 13 when Pickersgill Retirement Community hosts a Flag Day Ceremony featuring patriotic songs and readings, and 260 flags from all over the world.

The flags are not just a stunning display of primary colors. Each features an explanation of its origin and symbols, such as snakes and bears and stars. It often includes juicy tidbits.

For instance, what role did Mrs. Custer play when it came to Custer's last stand? 

Mounting the display is no haphazard task for Knowles, 55, an automatic-fare-collection engineer for the Washington Metropolitan Area Transit Authority. He wants to dazzle people.

"I want to hear jaws hit the floor,"  said the Northern Virginia resident who has been collecting flags since he was 14.

"I have loved flags since I was about 8 years old, when we learned about 'The Star-Spangled Banner' in elementary school," he said. "I thought the Revolutionary War flags were really cool, with the pine trees and snakes and other strange emblems."

The flags, which have been hung in Pickersgill's auditorium and on the on the 8-foot-high walls of the hallways that serve its 225 residents, range in size from a 9-foot by 17-foot American flag to the 1-foot by 2-foot flag of the U.S. Territory of Guam.

The colorful collection goes far beyond the flags of states and foreign countries. There are city flags and military flags as well, and most flags come with a story. 

• The Gonzales Banner of 1835 represents the group of Texans who captured Gonzales, Mexico, "with very little effort" during the Texas War for Independence from Mexico that year. Afterward, the Mexicans sent a message to the Texans requesting the return of their cannon.

The Texans responded by raising the banner that shows a cannon and a Texas star and a dubious invitation, "Come and Take It."

• The flag for the short-lived California Republic, which was founded in 1846, features a grizzly bear and a star. The republic lasted only 25 days.

• Custer's Battle Flag is a replica of the one flown by the ill-fated Gen. George Armstrong Custer, which was sewn by his wife, Libbie, and delivered to him by her on the battlefield of Dinwiddle Court House near Petersburg, Va., in 1865. But a stitch in time didn't save him.

He flew the flag during every battle for the rest of his life, which lasted only until 1876 when he lost both the flag and is life during the Battle of the Little Big Horn.

• Polk's Corps Flag, which was a banner for the Army of Tennessee during the Civil War, was adopted after Maj. Gen. Leonidas Polk became convinced there was some confusion between  the Stars and Stripes and the Stars and Bars.

The hour-long Flag Day ceremony at Pickersgill is always well attended, according to Jim Strom, Pickersgill's senior director of marketing and development. 

"It's very important to the residents. They are very patriotic and many of them are veterans," Strom said.

It was Knowles' late mother, Phoebe Knowles, who nurtured his interest in flags when he attended Pleasant Plains and Cromwell Valley elementary schools.

It is also because of his mother that, for the past 10 years, Knowles has put the flags on display for more than a month for Pickersgill residents and their visitors to enjoy.

He came up with the idea in 1994 when his mother was 74. Her small apartment in Baltimore had become too much for her and her fervent wish was to live in Pickersgill, where she had once volunteered.

He was "sweating bullets" to make it happen, he said, thinking his offer to mount a flag display might make her an even more appealing candidate.